/poosh"euhr/ , n.
1. a person or thing that pushes.
2. Slang. a peddler of illegal drugs.
3. Aeron. an airplane that is driven by pusher propellers.
4. Naut. one of the masts abaft the mizzen on a sailing vessel having more than three masts, either the sixth or seventh from forward. Cf. driver (def. 10b), spanker (def. 1b).
5. Railroads. a helper attached to the rear of a train, usually to provide extra power for climbing a steep grade.
[ 1585-95; PUSH + -ER 1 ]