1a \'a\ n, pl a's or as \'az\ often cap, often attrib (bef. 12c) 1 a : the 1st letter of the English alphabet b : a representation of this letter c : a speech counterpart of orthographic a 2 : the 6th tone of a C-major scale 3 : a graphic device for reproducing the letter a 4 : one designated a esp. as the 1st in order or class 5 a : a grade rating a student's work as superior in quality b : one graded or rated with an A 6 : something shaped like the letter A - Unattributed Author,