1. An upstart.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• akipjack,
• zkipjack,
• xkipjack,
• dkipjack,
• ekipjack,
• wkipjack,
• sjipjack,
• smipjack,
• slipjack,
• soipjack,
• siipjack,
• skupjack,
• skjpjack,
• ski-jack,
• skipjak,
• skippjack,
• skixjack,
• skipjakk,
• snippacck,
• swiahack

The adjective form of the word "skipjack" is "skipjack". The word does not change when used as an adjective.