A brand of swimwear, especially men's swim briefs.
Speedos are often associated with swimming, beaches, and athletic activities.
Examples:
He wore a red speedo at the beach.
I need to buy a new speedo for my swimming lessons.
The speedo is too tight for me.
I think I look funny in a speedo.
In the race, everyone wore a speedo to swim faster.
He always wears a speedo when he goes swimming.