Finish inside; make an effort to be up to date (6)
I believe the answer is:
trendy
'date' is the definition.
(thesaurus)
'finish inside make an effort' is the wordplay.
'finish' becomes 'end' (synonyms).
'inside' indicates putting letters inside.
'make an effort' becomes 'try' (to make an effort is to sincerely try).
'end' put inside 'try' is 'TRENDY'.
'to be up to' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for trendy that I've seen before include "Chic (colloq.)" , "Smart" , "Consciously fashionable" , "following fashion" , "'Hip, fashionable (6)'" .)