Put a stop to tips for yesteryear (4)
I believe the answer is:
past
'yesteryear' is the definition.
('past' can be a synonym of 'yesteryear')
'put a stop to tips for' is the wordplay.
'put' is an insertion indicator.
'to tips' says to take the final letters (I've seen 'tip' mean this).
'for' becomes 'st' (I can't explain this - if you can you should believe this answer much more).
The last letter of 'stop' is 'p'.
'p'+'st'='pst'
'a' placed into 'pst' is 'PAST'.
Can you help me to learn more?
(Other definitions for past that I've seen before include "The time that has elapsed" , "Second visitor in 5 [A CHRISTMAS CAROL]" , "A person's earlier life history" , "Bygone" , "tense" .)