swimming trunks; swim trunks
Wasei-eigo from English 'swimming pants'; refers to men's or unisex swimwear bottoms, not full-length pants.
wasei-eigo (Japanese-coined English), from swimming pants
Before going to the pool, I bought new swimming trunks.
He is wearing blue swim trunks.
Variant with interpunct; less common in everyday writing.
Wasei-eigo from English 'swimming' + 'pants'. Despite the English source, it means swim trunks or shorts, not long pants.