n.
Function: conjunction
Date: circa 1950
1 : AND <the Smyth Report, plus an idea and some knowledge of bureaucracy, were all I needed ― Pat Frank> <eats alone, a hot beef sandwich plus a BLT plus apple pie ― Garrison Keillor>
2 : in addition to which <it was an achievement. Plus, I wrote the story and the musical score ― Jackie Gleason> <it's also pretty on my open shelves, plus it smells good ― Nikki Giovanni>
usage The preposition plus has long been used with a meaning equivalent to and (as in “ two plus two ” ); it is not, therefore, very surprising that in time people have begun to use it as a conjunction much like and. Sense 2 is considered to be an adverb by some commentators. It is used chiefly in speech and in informal writing.