Swab and Shipmate

Swab noun - One who operates or navigates a seagoing vessel.

Shipmate and swab are semantically related In some cases you can use "Shipmate" instead a noun "Swab".

Shipmate noun - An associate on the same ship with you.

Swab and shipmate are semantically related in sailor topic. Sometimes you can use "Swab" instead a noun "Shipmate", if it concerns topics such as person who travels by sea, person who makes living on the sea.