Mate
The Cyclopedic Law Dictionary · Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
The Cyclopedic Law Dictionary
In maritime law
The officer next in rank to the master on board a merchant ship or vessel. In such vessels there is always one mate, and sometimes a second, third, and fourth mate, according to the vessel's size, ahd the trade in which she may be engaged. When the word "mate" is used without qualification, it always denotes the first mate; and the others are designated as above. On large ships the mate is frequently styled "first officer," and the second and third mates, "second" and "third" officers.
Parlish, Sea Off. Man. 83-140.