Definition

Adjective or prefix

  1. A variety of gear and rigging, usually small or of secondary purpose.

Noun

  1. A small flag flown from the bow.
  2. A cargo jack or jack screw.
  3. A British naval seaman whose station was on the masts and yards of square-rigged ships.

Origin

First definition, probably earlier than the 16th century. Second definition, probably earlier than the 17th century. Both definitions possibly derived from the Middle and Old French, jacques, a colloquialism for small.

Comments

There are many terms where “jack” is used as a prefix or adjective. As to the second definition, a jack is a national ensign flown from a jackstaff on the stem of a naval vessel when it is at anchor. Another type of flag would be a Pilot Jack which signals the need for a pilot (to guide the ship into a harbor, for example).

A jack could also refer to a cargo jack or jack screw. A piece of equipment used in a cargo hold for moving heavy cargo or for compressing cargo, such as cotton, into small spaces to increase carrying capacity. In British naval parlance, a jack was originally an Able Seaman whose duty station was on the masts and yards of a square-rigged ship.

References

Kemp, P. (1994). The Oxford Companion to Ships and the Sea. Oxford University Press.

King, D., Hattendorf, J.B, & Estes, J.W. (1997). A Sea of Words: A Lexicon and Companion for Patrick O’Brian’s Seafaring Tales (2nd Ed.). Owl Books.

Rogers, J.G. (1985). Origins of Sea Terms. Mystic Seaport.