Linguist in college once got across lake (8)
I believe the answer is:
polyglot
'linguist' is the definition.
(synonyms)
'college once got across lake' is the wordplay.
'college once' becomes 'poly' (short for polytechnic, former type of college).
'across' is an insertion indicator.
'lake' becomes 'L' (geographical abbreviation).
'got' enclosing 'l' is 'glot'.
'poly'+'glot'='POLYGLOT'
'in' acts as a link.
(Other definitions for polyglot that I've seen before include "Speaker of many languages" , "Bible" , "One speaks several languages" , "Person who knows several languages" , "Linguist" .)