Freedom in empty pretentious truisms (10)
I believe the answer is:
platitudes
'truisms' is the definition.
(I know this)
'freedom in empty pretentious' is the wordplay.
'freedom' becomes 'latitude' (latitude is a kind of freedom).
'in' indicates putting letters inside.
'empty' says to hollow out the word (remove centre letters).
'pretentious' with its centre removed is 'ps'.
'latitude' placed within 'ps' is 'PLATITUDES'.
(Other definitions for platitudes that I've seen before include "trite comments" , "boring texts" .)