- 1c (c's) the third letter of the English alphabet “Cat” begins with (a) C/“C.”
- 2(music) the first note in the scale of C major see also middle C
- 3 the third highest grade that a student can get for a course, test, or piece of work She got a C inPhysics.
NAmE//si//[countable, uncountable] (pl. Cs, C's