Well-liked tree outside university (7)
I believe the answer is:
popular
'well-liked' is the definition.
(similar in meaning)
'tree outside university' is the wordplay.
'tree' becomes 'poplar' (poplar tree is a kind of tree).
'outside' means one lot of letters goes inside another.
'university' becomes 'u' (abbreviation for university).
'poplar' going around 'u' is 'POPULAR'.
(Other definitions for popular that I've seen before include "Widely liked" , "Pleasing to many" , "Hot" , "Well-liked" , "In demand" .)