There are a total of 28 8-letter words containing 'jack', and the number may vary in different dictionaries. You can specify the dictionary and order.

• bluejack ₂₉
• bootjack ₂₇
• carjacks ₂₇
• flapjack ₃₁
• highjack ₃₀
• hijacked ₂₇
• hijacker ₂₆
• jackaroo ₂₄
• jackboot ₂₇
• jackdaws ₂₈
• jackeens ₂₅
• jackeroo ₂₄
• jacketed ₂₅
• jackfish ₂₉
• jacklegs ₂₇
• jackpots ₂₇
• jackroll ₂₆
• jackshit ₂₆
• jacksies ₂₄
• jackstay ₂₆
• rejacket ₂₄
• skipjack ₃₁
• skyjacks ₃₀
• slapjack ₂₈
• pumpjack ₂₇
• jackings ₂₂
• manjacks ₂₃
• whipjack ₂₉

There are 28 8-letter words containing jack in the well-known word game dictionary, 22 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 26 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 24 in the Words with Friends (WWF) dictionary.