Main Entry: boat·swain

Variant(s): or bosun also bos'n or bo's'n or bo'sun \ˈbō-s^ən\

Function: noun

Etymology: Middle English bootswein, from boot boat + swein boy, servant — more at swain

Date: 14th century

1 : a petty officer on a merchant ship having charge of hull maintenance and related work
2 : a naval warrant officer in charge of the hull and all related equipment