IPA: //prɛˈstæmpt//
KK: /prɛˈstæmpt/
Describing something that has already been marked or stamped before use.
The prestamped envelopes made mailing the invitations much easier.
Prestamped → It is formed from "pre-" (meaning before) and "stamp" (from Old English "stampian", meaning to impress or mark). The word "prestamped" means marked or impressed before a certain time or event.
Think of something that is marked or impressed "before" an event — "pre-" means before, and "stamp" means to mark.