bachelor

\ \ [13] The ultimate origins of bachelor are obscure, but by the time it first turned up, in Old French bacheler (from a hypothetical Vulgar Latin *baccalāris), it meant ‘squire’ or ‘young knight in the service of an older knight’.

\ \ This was the sense it had when borrowed into English, and it is preserved, in fossilized form, in knight bachelor. Subsequent semantic development was via ‘university graduate’ to, in the late 14th century, ‘unmarried man’. A resemblance to Old Irish bachlach ‘shepherd, peasant’ (a derivative of Old Irish bachall ‘staff’, from Latin baculum, source of English bacillus and related to English bacteria) has led some to speculate that the two may be connected.

\ \ English baccalaureate [17] comes via French baccalauréat or medieval Latin baccalaureātus from medieval Latin baccalaureus ‘bachelor’, which was an alteration of an earlier baccalārius, perhaps owing to an association with the ‘laurels’ awarded for academic success (Latin bacca lauri meant literally ‘laurel berry’).