- the officer of a merchant vessel next in command beneath the second mate.
Also called third officer.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for third mate
Historical Examples of third mate
This set everybody in motion, and the captain and third-mate were on deck in a minute.
As third-mate, it was my duty to see the boxes taken out of the hold, and the opium delivered.