n.
Function: conjunction
Date: before 12th century
1 a : with the result that <the acoustics are good, so every note is clear> b : in order that <be quiet so he can sleep>
2 archaic : provided that
3 a : for that reason : THEREFORE <don't want to go, so I won't> b (1) ― used as an introductory particle < so here we are> often to belittle a point under discussion < so what?> (2) ― used interjectionally to indicate awareness of a discovery < so , that's who did it> or surprised dissent
– so as to : in order to
usage Although occas. condemned, use of so to introduce clauses of result (sense 1a) and purpose (sense 1b) is standard. In sense 1b so that is more common in formal contexts than so alone.