Feeling cheerful. Someone who's cheerful is spirited and happy. Your sister might be so cheerful that you hear her whistling joyfully first thing in the morning. If you're full of good humor and optimism, your friends probably describe you as cheerful. A cheerful bus driver, restaurant server, or calculus teacher can brighten your whole day. Cheerful means "full of cheer," and cheer, which came to mean "good mood or spirit," started out in the 13th century meaning "the face," from the Late Latin cara, "face," and its Greek root, kara, "head."