DictionaryflyClothing opening
noun

fly

The front opening in trousers, fastened with a zipper or buttons.

These jeans have a button fly instead of a zipper.

Etymology

The opening name developed from a flap of material. The flap covers the fastening and opening at the front of trousers, extending that covering sense.

More examples

  • He checks that his fly is closed before the interview.
  • The zipper on my fly keeps getting stuck.
  • She sews a new button onto the fly of his trousers.

Forms

fly · flies

Similar words

placket
A placket is a finished garment opening, not necessarily in pants.
opening
An opening is any gap, not specifically a pants closure.