Noun has 2 senses

• jack oak(n = noun.plant) blackjack, blackjack oak, quercus marilandica - a common scrubby deciduous tree of central and southeastern United States having dark bark and broad three-lobed (club-shaped) leaves; tends to form dense thickets;


• jack oak(n = noun.plant) northern pin oak, quercus ellipsoidalis - small to medium deciduous oak of east central North America; leaves have sharply pointed lobes;