Delight

SEND

Think of a four-letter word meaning "to cause great happiness" that also fits the phrase "a letter you might ___ to a friend."

"Delight" hints at the answer "SEND" through a playful twist on the phrase "send delight." The word "send" sounds like "S-end," where "S" is the abbreviation for "south," and "end" refers to the last letter of "delight" (which is "T"). But in this case, it’s a homophone trick—"send" itself sounds like "cent," a coin that might bring delight when received. The clue relies on the solver hearing the word rather than dissecting its letters.