jiggermast

[jig-er-mast, -mahst; Nautical jig-er-muh st] /ˈdʒɪg ərˌmæst, -ˌmɑst; Nautical ˈdʒɪg ər məst/
noun, Nautical
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.
Origin
1825-35; jigger1 + mast1
British Dictionary definitions for jiggermast

jiggermast

/ˈdʒɪɡəˌmɑːst/
noun
1.
(nautical) any small mast on a sailing vessel, esp the mizzenmast of a yawl Sometimes shortened to jigger