Celebrity turning up in a tree, possibly (6)
I believe the answer is:
repute
'celebrity' is the definition.
(I've seen this before)
'turning up in a tree possibly' is the wordplay.
'turning' is a reversal indicator.
'in' means one lot of letters goes inside another.
'possibly' indicates anagramming the letters.
'up' written backwards gives 'pu'.
'tree' is an anagram of 'rete'.
'pu' inserted within 'rete' is 'REPUTE'.
(Other definitions for repute that I've seen before include "State of high esteem" , "Character, esteem" , "Generally held opinion" , "General view or opinion of an individual, may be ill" , "Known character, standing" .)