1. [n]  a gambling game using cards; the object is to hold cards having a higher count than those dealt to the bank up to but not exceeding 21
2. [n]  a piece of metal covered by leather with a flexible handle; used for hitting people
3. [n]  a common scrubby deciduous tree of central and southeastern United States having dark bark and broad 3-lobed (club-shaped) leaves; tends to form dense thickets
4. [v]  exert pressure on someone through threats

BLACKJACK is a 9 letter word that starts with B.