English question, please help. thanks?

For those who are not an English-dominant speaker, they would typically refer to them as "pants."

However, they are indeed actually called "trunks," or more specifically - as you have kindly provided - "swim/swimming trunks."

Either way, both refer to the same thing, and I imagine anyone who hears either would acknowledge what one is implying without much difficulty.

if you're a guy you wear a swimming trunks, a trunks (spelled with an 's' singular or plural) means shorts or brief for men, it could come in V cut covering the groin or straight cut covering to the thighs. The word "pants" incidentally, makes quite a joke between the americans and the brits. The brits always refer panties are for women and pants are for guys, however the americans has taken a different outlook, they always refer their trousers as pants and sometimes it sound funny to hear them ironing their pants while they're watching TV.

Swim trunks is the most common. But you can also say swimming trunks. I've never heard anyone call them "pants"

Nobody uses the terms swim pants or swimming pants, but most people call them swimming trunks.

swimming trunks