There are a total of 18 7-letter words containing 'jack', and the number may vary in different dictionaries. You can specify the dictionary and order.

• carjack ₂₆
• hijacks ₂₅
• jackals ₂₄
• jackass ₂₃
• jackdaw ₂₇
• jackeen ₂₄
• jackers ₂₃
• jackets ₂₃
• jackies ₂₃
• jacking ₂₆
• jackleg ₂₆
• jackpot ₂₆
• jackses ₂₃
• jacksie ₂₃
• skyjack ₂₉
• jackman ₂₂
• jackmen ₂₂
• manjack ₂₂

There are 18 7-letter words containing jack in the well-known word game dictionary, 12 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 17 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 15 in the Words with Friends (WWF) dictionary.