Dinneen's Focloir Gaedhilge agus Bearla defines the Irish word crosan as (1) a cross-bearer, (2) a seabird, a kind of sea-pigeon, and (3) a scurra, a satirist; a buffoon, a comedian; a cheat, a villain. O Donaill's
later Focloir Gaeilge Bearla gives (1) mimic, jester; a satirist, a scurrilous person, and (2) razorbill, starfish.
Blas an seachtu crosain means "surfeited feeling, cloying taste". Persons bearing the surname Mac an Chrosain (son of Crosan) will, no doubt, make their own choice. (The only apparent connection between the two disparate meanings is perhaps "razorbill" and "satirist".)
P. W. Joyce in his Social History of Ancient Ireland defines crosan as "gleeman", a word which The Shorter Oxford Dictionary defines as "a professional entertainer; especially a singer, musician, or minstrel". Q. And if people bearing this surname ever have a clan "get-together", and wish to add authenticity, Joyce tells how they should deck themselves out.
Quoting from the Story of Mesca Ulad, Joyce describes Concobar's royal fool Roimid as he stood amusing a delighted crowd who surround him:
"He had a black, pointed, thick head of hair; his face (painted) a bluish-black, like an Ethiopian; his eyes were large, wide open, and seemed all white (on account of the blackened face); he wore a ribbed bratt all in folds, fastened with a brass clasp at his breast; at his side hung a melodious little bell (cluicin ceolbind) which he often struck with a bronze wand to procure attention, making such a sweet tinkle that it gave pleasure and delight to the arch-king and to the whole host."
"There are two distinct septs of Mac an Chrosain. The one which is now easily identified is that of Tirconnell, whose present-day representatives are to be found more numerous in Tyrone and Co Derry than in Donegal: in Tyrone the prefix Mac has been retained but in Co Derry it has been to a large extent dropped." (MacLysaght's More Irish Families). The other sept were hereditary bards to the O'Mores and O'Connors of counties Laois and Offaly, and the Chancery Rolls of 1550 notes a pardon for Owen Mac Crossan of Ballymacrossan, Co Offaly, described as "a rhymer".
In the late 16th century these Mac Crossans changed their surname to the English Crosbie ("village/farm with cross(es)" on; old Norse kross is from Irish and ultimately from Latin"). The first is said to have been Patrick Crosbie, who, having deserted the O'Mores and thrown in his lot with the English, obtained lands in Ardfert, Co Kerry.
Those Crosbies extended their lands in that county, possessing, among other properties, the historic estate of Ballyheigue. "As early as 1610 Pierce Crosbie, already described as "a very powerful Kerry landlord" and also a noted intriguer, was one of the Commissioners for the Plantation of Ulster, just at the time the aforesaid Patrick was offering lands in Co Kerry on which to settle the transplanted "seven septs of Leix". (More Irish Families).
The year 1319 was a bad year for bishops. In that year Henry Mac an Chrosain, bishop of Raphoe died, as did the bishop of Clogher and the bishop of Clonfert. Richard Mac Crossan was another 14th century bishop of Raphoe. The episcopal leanings was also found among those that had changed their name to Crosbie, John Crosbie being Protestant bishop of Ardfert from 1600 to 1620.
The Crosbies were on the Irish side in the Cromwellian and Williamite invasions; Sir Piers Crosbie, a Queen's County Protestant proprietor in 1640 "turned Papist and led a troop of horse with the Irish", and in 1687 Sir Thomas Crosby was an officer in James II's army. Despite all that they held on to their estates. Owners of Land of One Acre and Upwards (1876) shows them with 9,913 acres at Ardfert Abbey and 13,422 acres at Ballyheigue Castle. There were two holdings of 23 and 844 acres also in Co Kerry.
The burning of their residence, Ardfert Abbey, in the early 1920s ended the Crosbie connection with Kerry; the only Ardfert reminders are the gate lodge and the village pump.
Owners shows two Crossan holdings, 103 and 983 acres; four in Co Donegal of seven, 45, and eight, and 889 acres McCrossan holdings, with two McCrossan holdings in Co Tyrone, 1,381 and 1,901 acres.
Current telephone directories south of the Border list 53 entries of McCrossan and 135 of Crossan. North of the Border there are 75 McCrossans and 90 Crossans. Ballymacrossan in the Co Offaly parish of Geashill, is the anglicised form of Baile Mhic Crosain.