Coss \Coss\ (k[o^]s), n. [Cf. Pers. k[=o]s a road measure of about two miles; or Skr. kr[=o][,c]a.] A Hindoo measure of distance, varying from one and a half to two English miles. --Whitworth.
Source: Webster's Revised Unabridged Dictionary (1913)
Coss \Coss\, n. [It. cosa.] A thing (only in phrase below).
Rule of Coss, an old name for Algebra. [It. regola di cosa rule of thing, the unknown quantity being called the cosa, or the thing.]