/jig"euhr mast', -mahst'/ ; Naut. /jig"euhr meuhst/ , n. Naut.
1. a small mast set well aft in a boat or ship; mizzenmast.
2. the fourth mast from forward in a ship having five or more masts.
Also, jigger mast . Also called jigger .
[ 1825-35; JIGGER 1 + MAST 1 ]