Also see definition of "Man-Child" in Word Study
Man-Child
MAN-CHILD [isbe]
MAN-CHILD - man'-child (American Standard Revised Version; "man child," the English Revised Version; not in the King James Version; mashtin beqir): The expression is used with the meaning of "male," but is found only in the description of the extermination of a whole family, where it is employed to express every male descendant of any age. It occurs in 1 Sam 25:22,34; 1 Ki 14:10; 16:11; 21:21; 2 Ki 9:8.
Also see definition of "Man-Child" in Word Study