sb. and a. (adv.) Chiefly Sc. Also 46 thresum, 6 thriesum. [L. THREE + -SOME.] A. sb. Three persons together; three forming a company.
1375. Barbour, Bruce, III. 420. It [boat] sa litill wes, þat It Mycht our þe wattir bot thresum flyt.
1549. Compl. Scot., xv. 131. It is nocht possibil to gar thresum keip consel.
a. 1578. Lindesay (Pitscottie), Chron. Scot. (S.T.S.), I. 275. Mccleine echapit and thriesum with him.
1816. Scott, Bl. Dwarf, viii. The rest disperse by twasome and threesome through the waste, and meet me at the Trysting Pool.
1893. Stevenson, Catriona, xxix. We sat down to meat, we threesome.
B. adj. Consisting or composed of three; performed by three together; threefold, triple.
1839. New Monthly Mag., LVII. 42. Any thing like a country-dance, or a threesome or foursome reel.
1872. Morris, Love Is Enough (1873), 8. To have seen Your nimble feet tread down the green In threesome dance. Ibid. (1875), Æneid, V. 580. Then they in threesome order slip Their cloven ranks.
1878. H. H. Gibbs, Ombre, 4. Tresillo means a threesome game.
Mod. Sc. A threesome cluster of nuts. She does her back hair in a threesome plait.
b. quasi-adv. nonce-use: cf. FOURSOME 1 b.
1875. Morris, Æneid, VII. 639. Mail-coat threesome laid Of golden link.
Hence Threesomeness nonce-wd., the quality of existing in threes, triplicity.
1853. Athenæum, 15 Oct., 1216. What may be called the threesomeness of everything in the moral world.