Oxford English Dictionary
Bachelor:
Originally coined in 1297 by R. Gloucester's Chron. 453 Syre ȝong bacheler..þow art strong & corageus. Definition: A young knight, not old enough, or having too few vassals, to display his own banner, and who therefore followed the banner of another; a novice in arms.
Later in 1609 the word evolved to become 'Knight Bachelor', a knight of the lowest but most ancient order; the full title of a gentleman who has been knighted.
Again slightly later in 1614, the word bachelor began to take on educational pragmatics, used to describe one who has taken the first or lowest degree at a university, who is not yet a master of the Arts. By J. Selden in Titles of Honor 55 Dominus is now familiar for Sir to euery Batcheler of Art in the Schools. In September 2013 Bachelors Degree was a term added to the Oxford English Dictionary the degree awarded on successful completion of a undergraduate course.
Slag:
When the term slag was first coined it was primarily used to refer to a piece of refuse matter separated from a metal in the process of smelting.
