( n. )
A mechanical contrivance, an auxiliary machine, or a subordinate part of a machine, rendering convenient service, and often supplying the place of a boy or attendant who was commonly called Jack
( n. )
A mechanical contrivance, an auxiliary machine, or a subordinate part of a machine, rendering convenient service, and often supplying the place of a boy or attendant who was commonly called Jack
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012