a device for opening sealed containers: can opener.
the first of several theatrical numbers, variety acts, sports events, etc.: a humorous monologue as an opener.
cards in a hand, as a pair of jacks or better, that according to a given standard are worth enough to enable the holder to make the first bet of a deal.
as an initially stated reason or argument; at the outset; to begin with: Well, for openers, I don't have the money.