Most families have their own private domestic slang that outsiders just don't understand, writes Fionola Meredith.

FAMILY SLANG: it's the poetry of everyday life, adding a splash of creativity, colour and humour to the daily grind. And while most of us keep those strange little words behind closed doors, it seems there's barely a family around that doesn't have its own private domestic code.

Some limit their flights of linguistic fantasy to a few choice phrases, while others have accumulated such a slew of descriptive terms that it's practically a second language. For instance, who would have thought there would be so many words for pyjamas? Jims, mijjers, jim-jams and even the exuberant jim-jam-joolies are all common family terms for nightwear.

And there's a veritable flood of words for that iconic object of family life, the remote control, ranging from the onomatopoeic clicker, clacker or bleeper, through the Italian-inspired telecommando, to the rather sinister daddy buttons.

This is nothing new, of course. As children's writer AA Milne observed back in 1950, "[every] family has a language of its own, consisting of unintelligible catchphrases, favourite but not generally known quotations, obscure allusions, and well-tried but not intrinsically funny family jokes".

In the 1980s, Douglas Adams and John Lloyd's book, The Meaning of Liff, tapped into a similar vein of hilarity by attributing obscure definitions to place-names, many of them Irish. So Duleek is "the sudden realisation, as you lie in bed waiting for the alarm to go off, that it should have gone off an hour ago", while "Skibbereen" is "the noise made by a sunburned thigh leaving a plastic chair" and - most bizarrely of all - "Sligo" is "an unnamed and exotic sexual act which people like to believe that famous films stars get up to in private; for example, 'to commit Sligo'."

BUT TODAY MANY of these hidden family gems are coming to light as a result of the British-based "Kitchen Table Lingo" project. Researchers are hoping to round them all up in a new dictionary that, it's promised, will capture the "amazing, spontaneous innovation" of the English language. The rules are simple and fairly loose: the words must not have been included in a dictionary before, and they must have been in use by three or more people for at least a month. So far, the term "embuggerance" is one of the most popular nominations: employed by author Terry Pratchett to sum up his feelings of frustration at the encroachment of Alzheimer's disease, it was originally coined by a British defence official during the Falklands War.

Another submission is "snotfair"; a contraction of the familiar whine, "it's not fair", apparently used by academics to describe a meeting with a querulous student who is unhappy with his or her results. Many cherished family neologisms come from our own children's infancy, and their endearingly flawed attempts to get to grips with language. For instance, it's many years since Mike Hannon's son Paul, then aged eight, announced that he was "discompoosed" when he got home from a particularly riotous birthday party, but the term is still in everyday use in the Hannon family, meaning something between disconcerted and confused. Paul and his sister Jude also came up with another family favourite, "megeezers", which is a derisory term for over-cautious elderly drivers.

Meanwhile, Romy McKeever still thinks of starlings as "cheeky darlings" ever since her daughter coined the lovely term as a small child. Sometimes the whole extended family take up an amusing phrase, as Richard, an academic in his 40s, says, "now we all refer to the credit crunch, inflation and other financial alarms as the regression because of a bit of mis-speaking by a niece."

"We owe a great deal to children's creativity with language," says Loretta Todd, visiting professor in linguistics at the University of Ulster. "They have no fears about cutting and combining words to get their meaning across. What's more, people in general are inherently creative, and it's wonderful to see the sheer joy, the sense of novelty people take in using language. The Irish in particular take a terrific delight in it." While children's early stabs at language are charming, often it's the harassed parents' attempts to exert some control over chaos that end up becoming part of the language of everyday life. "The other day, a friend of mine gave me a strange look when I yelled "it's time for WFT" up the stairs to my children [aged 10 and 12]," says Chris, a teacher.

"That's family shorthand for the bedtime ritual of 'wee, face-wash and teeth'. You forget that these sayings sound funny to outsiders, but we've used that one for years. It comes to naturally to me, because I come from a family that loves to play with language. In fact, when I was a child, I was fascinated by words - still am, really - and I used to talk backwards quite fluently. Certain everyday phrases - things you would see on the side of lorries, like 'storage and removals' - were really juicy if you said them back to front. So storage and removals becomes 'egarots' and 'slavomer', which sound a bit like characters from Beckett. My kids think I'm crazy - but I love to see them really relishing language in the same way."

Of course, not all our everyday phrases come from the recent past. Many family words filtering down through the generations have their origins in local dialect. Blogger Mick Fealty says, "most of the words we used when I was growing up were, I would guess, commonplace at some earlier time. For instance, I remember 'dwammy' [an old Ulster Scots term, according to Loretta Todd], which meant you were not quite at yourself, a bit at sea."

Or, as with the remote control, if an item has a cumbersome name - or no name at all — that's the cue to come up with a suitable tag or nickname that may well end up sticking. Richard recalls, "I now think of those little forks that you can use to eat corn on the cob as 'doolets' because back in my flat-sharing days, when doing the washing up one evening, we had a discussion about whether they had a specific name. When someone suggested that if they didn't have a name, we should make one up, my friend Clare said 'do let's' which became the name."

Meanwhile, in Colm McGivern's home, "anything small and anonymous, especially related to DIY, is known as a 'McClatchy'." And sometimes the origin of long-established family phrases is entirely forgotten. Author Ian Samson says, "We have a system of measurements for second-helpings. A 'hooch' is a large one; a 'snooch' is mid-size; and 'ganooch' is small - but I can no longer recall where it came from."

OTHER COMFORTABLY familiar phrases come from school or college days. "At university, I learnt that when you wanted to lie down and take 40 winks in the middle of the afternoon, you would say 'I'm off to read some Greek'," says Sean (41). "The theory was that reading Greek involves awfully close attention to the script on the page and it's best to hold the book close to your eyes. That's best done lying down, holding the book vertically above your eyes. Naturally, within minutes sleep follows. So 'off to read Greek' sounds noble, self-improving and purposeful when actually you're just taking a snooze - an effective dodge".

Great leaps of linguistic imagination are not always necessary either. Media researcher Paul Caulfield says that in his family, "we use 'doot' for any random object you want or have lost - we say 'pass us the doot there . . .' and so on. Amazingly, most people know what you are referring to."

And sometimes, sheer forgetfulness is the motivation. William and his wife can never remember the names of their children's teachers. "So in homage to Eddie Izzard they're all just called 'Mrs Badcrumble' [after the Scottish clarinet teacher character created by the comedian] - and the kids seem fine with that."

The 20th-century American etymologist Allen Walker Read was a great fan of creative family slang; dubbing it "the effervescing of language", he wrote that "one of the greatest gifts that can come to a speaker of a language is the freedom to move about among the possible patterns that the language provides for him. This feeling of 'at-homeness' develops and flowers in the family circle".

For many families and other closely connected social groups, the invention and use of their own secret language is more than a rich private vernacular: it's the bond that holds them together.