Pitch a tent on American college grounds (6)
I believe the answer is:
campus
'college grounds' is the definition.
(I've seen this before)
'pitch a tent on american' is the wordplay.
'pitch a tent' becomes 'camp' (I've seen this before).
'on' is a charade indicator (letters next to each other).
'american' becomes 'us'.
'camp'+'us'='CAMPUS'
(Other definitions for campus that I've seen before include "academic haunt" , "University premises" , "educational location" , "buildings in Nottingham, say" , "student quarters" .)