marine

Recorded in English since around 1420 as Middle English marin, borrowed from Middle French marin, from Old French, ultimately from Latin marinus, 'of the sea,' itself from mare, 'sea.' That Latin root traces back to Proto-Indo-European *móri, 'body of water, lake.'

The word entered English simply meaning 'of the sea,' and the facts don't record much shift beyond that — though its modern pronunciation is thought to owe something to the influence of the modern French word marine.

The same ancient root, PIE *móri, also gave rise to Old English mere ('sea, lake, pool, pond'), as well as Dutch meer and German Meer — all descending from Proto-Germanic *mari.