cav·er 
(kāvər)
(kāvər)n.
1. One that caves.
2. One who explores or studies caves, especially as a sport or recreational pursuit.
- 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
- protoderm
- protodermal