1. cos(n = noun.linkdef) cosine - ratio of the adjacent side to the hypotenuse of a right-angled triangle;
is a kind of circular function, trigonometric function
2. cos(n = noun.food) cos lettuce, romaine, romaine lettuce - lettuce with long dark-green leaves in a loosely packed elongated head;
is a kind of lettuce
cos, n. a variety of lettuce with crisp narrow leaves forming a long upright head.
cos, abbr. cosine.
cos, conj. & adv. (also 'cos) colloq. because.
Etymology:
abbr.