A chap is an informal, somewhat old-fashioned word for a man or boy. You might read in a classic adventure story about “a brave young chap” who helps solve a mystery, or hear someone say “he's a good chap” to mean he's a decent, reliable person. The word sounds friendly and casual, like calling someone a guy or a fellow.

British people use chap more often than Americans do, though you'll still encounter it in older American books and movies.

You might also hear the word in “old chap,” a warm way of addressing a friend, similar to “old buddy.” When someone calls another person “a fine chap” or “a decent chap,” they're expressing respect and affection, suggesting the person has good character and can be counted on.