Small label on odd thing for celebration (4,5)
I believe the answer is:
stag night
'celebration' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'small label on odd thing' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'label' becomes 'tag' (synonyms).
'on' indicates putting letters inside.
'odd' indicates anagramming the letters.
'thing' is an anagram of 'night'.
'tag' inserted inside 'night' is 'tagnight'.
's'+'tagnight'='STAG NIGHT'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for stag night that I've seen before include "Final fling" , "Celebration before wedding" , "Rowdy party" , "when men behave badly?" , "Premarital do" .)