Word play was the clever and witty use of words and meaning. A pun was one example of word play, as was the deliberate, literal interpretation of idioms.
Tuvok told Neelix that his answer was merely word play, after it was revealed that the answer to Neelix' riddle of how a stranded ensign survived stranded for a year with only a calendar by eating the dates. Tuvok argued that it has no basis in reality, but later reconsidered the riddle and it later occurred to him that the ensign could also have eaten the sundaes. (VOY: "Riddles")