Dictionary
cap'ital let'ter
a letter of the alphabet that usually differs from its corresponding lowercase letter in form and height, as
A, B, Q, and
R as distinguished from
a, b, q, and
r: used as the initial letter of a proper name, the first word of a sentence, etc. Also called
capital. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.