The term PLAYFUL PRANK is composed of five words, each with a different number of letters. The first word is LARK, which is a four-letter word meaning to engage in lighthearted or mischievous behavior. The second word is DIDO, which is also a four-letter word and refers to a prank or joke. The third word is ANTIC, a five-letter word that means to behave in a silly or playful manner. The fourth word is CAPER, a five-letter word that means to engage in a mischievous or playful act. The fifth and final word is MONKEYSHINE, an eleven-letter word that means to engage in a mischievous or playful prank. Together, these five words form the phrase PLAYFUL PRANK, which can be used to describe any kind of mischievous or playful activity.