late 14c., capitayn, "a leader, chief, one who stands at the head of others," from Old French capitaine "captain, leader," from Late Latin capitaneus "chief," noun use of adjective capitaneus "prominent, chief," from Latin caput (genitive capitis) "head" (from PIE root *kaput- "head").
The military sense of "officer who commands a company" (the rank between major and lieutenant) is from 1560s; the naval sense of "officer who commands a man-of-war" is from 1550s, extended to "master or commander of a vessel of any kind" by 1704. Sporting sense "leader of the players on a team" is recorded by 1823. The words inb other Germanic languages are also from French.
Proto-Indo-European root meaning "head."
It forms all or part of: achieve; behead; biceps; cabbage; cabochon; caddie; cadet; cap; cap-a-pie; cape (n.1) "garment;" cape (n.2) "promontory;" capital (adj.); capital (n.3) "head of a column or pillar;" capitate; capitation; capitulate; capitulation; capitulum; capo (n.1) "leader of a Mafia family;" capo (n.2) "pitch-altering device for a stringed instrument;" caprice; capsize; captain; cattle; caudillo; chapter; chef; chief; chieftain; corporal (n.); decapitate; decapitation; forehead; head; hetman; kaput; kerchief; mischief; occipital; precipice; precipitate; precipitation; recapitulate; recapitulation; sinciput; triceps.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit kaput-; Latin caput "head;" Old English heafod, German Haupt, Gothic haubiþ "head."
"captain or master of a ship," late 14c., from Middle Dutch scipper, from scip (see ship (n.)). Compare English shipper, used from late 15c. to 17c. in sense "skipper." Transferred sense of "captain of a sporting team" is from 1830.
initialism (acronym) from shit out of luck (though sometimes euphemised), 1917, World War I military slang. "Applicable to everything from death to being late for mess" [Russell Lord, "Captain Boyd's Battery, A.E.F.," c. 1920]
"the science of plants," 1690s, from botanic. The -y is from astronomy, etc. Botany Bay in Australia was named by Captain Cook (1770) on account of the great variety of plants found there; later it was a convict settlement (1778).