smooth·bore also smooth bore 
(smthbôr)
(smthbôr)adj.
Having no rifling within the barrel. Used of a firearm.
n.
A firearm having no rifling.
- prothallium
- prothallus
- prothesis
- prothetic
- prothetically
- prothonotarial
- prothonotary
- prothonotary apostolic
- prothonotary apostolic
- prothonotary warbler
- prothoracic
- prothoracic gland
- prothorax
- prothrombin
- protist
- protistan
- protistology
- protium
- proto-
- Proto-Algonquian
- protoceratops
- protocol
- protocolar
- protocolary
- protoctist