Tie-on label cheers granny at first (3)
I believe the answer is:
tag
'tie-on label' is the definition.
(I've seen this before)
'cheers granny at first' is the wordplay.
'cheers' becomes 'ta' (I've seen this in other clues).
'at first' indicates taking the first letters.
The first letter of 'granny' is 'g'.
'ta'+'g'='TAG'
(Other definitions for tag that I've seen before include "Identity badge" , "stock quotation" , "Children's chasing game" , "Tab" , "Label (to attach)" .)