(knitting machines) A thin iron plate operated by the jack to depress the loop of thread between two needles.

(architecture) Any timber, such as a rafter, rib, or studding, which, being intercepted, is shorter than the others.

(informal) A person who vocalizes quietly, in a whispering manner, or, ironically, one who is loud and outspoken.

Alternative form of Jack-in-the-pulpit

A hydraulic jack (lifting device) mounted on wheels, and equipped with a long handle which also acts as a pump handle, which can be pulled to wherever it is needed.

plural of jack-rabbit (alternative form of jackrabbits).

(derogatory) A self-important but minor official.

A card game similar to all fours.

plural of jack mackerel

An automaton, on a clock, that strikes a bell every quarter hour