What does bosun mean?
A bosun (also spelled boatswain, and historically bo'sun or bo's'n) is the warrant or petty officer aboard a ship who supervises the deck crew and is responsible for the upkeep of the vessel's rigging, anchors, cables, and general deck equipment. The word is a phonetic rendering of how sailors have actually pronounced 'boatswain' for centuries — with a silent 't' and 'ai' collapsed into a single unstressed syllable — and this spoken form has become fully standard in its own right. The bosun occupies a crucial middle rank: answerable to the officers above but working shoulder to shoulder with the sailors below, often the most experienced seaman on board and traditionally the one who piped commands with a special whistle known as the bosun's call. Today the term survives most prominently in merchant navies, navies, tall-ship sailing, and maritime literature, where it evokes centuries of seafaring tradition.
nounA bosun is the officer on a merchant ship responsible for the deck crew and the maintenance, rigging, and equipment of the vessel. It is the standard phonetic spelling of 'boatswain', whose pronunciation it preserves.
- The ship's officer in charge of the deck crew, rigging, anchors, and general maintenance of the hull and equipment.
"The bosun bellowed orders across the deck as the crew scrambled to furl the sails before the storm."
"The bosun inspected every inch of rigging before the ship left port."
"As bosun, she was responsible for training the new hands in knot-work and deck seamanship."
Regular plural; occasionally written "bo'suns" in older texts.
"Over his thirty years at sea he served under four different bosuns."
It's spelled like 'bow-sun' but pronounced 'BOH-sun' — a 500-year-old sailor's shortcut that eventually became the official spelling.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bosun
Bosun originated as a phonetic contraction of 'boatswain', itself formed from 'boat' plus 'swain', the latter an Old English and Old Norse word meaning servant or attendant (from Old Norse 'sveinn'). The compound dates to the 15th century in English, and the reduced pronunciation was reflected in spellings like 'botsun' and 'bo'sun' by the 16th–17th centuries. The word 'swain', now poetic for a lover or country lad, shares this same Germanic root, making it a true etymological sibling of the nautical title.
Related word forms
How bosun is actually used
Nautical register throughout — the word appears mainly in maritime contexts, historical fiction, and naval writing. It is slightly informal relative to 'boatswain' but has become so standard that many modern dictionaries list it as an equal variant rather than merely an abbreviation. The apostrophized forms bo'sun and bo's'n appear chiefly in older or dialectal writing.
Easily confused with bosun
Boatswain is the original full form of the rank while bosun is simply its contracted respelling — they denote the same position, though only bosun reflects the actual pronunciation.
A bosom is a person's chest or a close embrace, unrelated to the nautical officer spelled bosun despite their similar appearance.