Swimsuit
Part of speech: noun
Definition: A tight-fitting garment worn for swimming.
Example sentence: I made my career off posing in swimsuits and doing all the swimsuit issues and posters, but I will tell you that that little bit of material on an itsy-bitsy bikini - taking that off was very nerve-racking the first time.
Swimwear
Part of speech: noun
Definition: Items of clothing appropriate for swimming