the word 'submariner' is a modern english compound built from classical elements. the prefix 'sub-' derives from latin 'sub', meaning 'under', a preposition with proto-indo-european origins. it is attached to the root 'marin', adapted from the latin 'mare' for 'sea', which itself traces back to the pie root mori-. the agentive suffix '-er', of old english origin, is then added to denote a person associated with the preceding concept. thus, the literal construction 'one who works under the sea' logically and directly yields the modern professional term for a submarine crew member.

Structure: sub (under) + marin (sea) + er (agent suffix) sub- (latin prefix, meaning 'under, below'); marin (from latin 'mare', meaning 'sea'); -er (old english agent suffix, meaning 'one who does or works with').