From Dutch 'boeg' (shoulder, ship's front), PIE *bʰewgʰ- (to bend) — literally 'the shoulder' of the ship, the curved part meeting the water.
The forward end of a ship or boat, designed to cut through the water and reduce resistance; the prow.
From Low German 'bug' or Dutch 'boeg' (the bow of a ship, the shoulder), from Proto-Germanic *bōguz (a bend, a shoulder, a bow), from PIE *bʰewgʰ- (to bend). The nautical bow is literally 'the shoulder' of the ship — the curved, bent part at the front that meets the water. The word is related to English 'bough' (a branch — something that bends) and
English has three different words spelled 'bow': the front of a ship (pronounced to rhyme with 'cow'), a weapon for shooting arrows (rhyming with 'go'), and the act of bending in greeting (rhyming with 'cow'). All three derive from the same PIE root *bʰewgʰ- (to bend) — they are the same ancient word that specialized into different meanings.