In Royal Navy jargon, a man-of-war (also man-o'-war, or simply man)[1][2] was a powerful warship or frigate of the 16th to the 19th century, that was frequently used in Europe.
Although the term never acquired a specific meaning, it was usually reserved for a sailing ship armed with cannon.
The man-of-war was developed in Portugal in the early 15th century from earlier roundships with the addition of a second mast to form the carrack.
In process of time the word 'ship' was discarded as unnecessary and there remained the phrase 'a man-of-war.'"
– Talbot.The man-of-war design developed by Sir John Hawkins was a type of galleon which had three masts, each with three to four sails.