Celebratory communication shows wit (4)
I believe the answer is:
card
This could be a double definition.
'celebratory communication' is the first definition.
'card' can be an answer for 'communication' (card is a kind of communication). I'm unsure of the 'celebratory' bit.
'wit' is the second definition.
(synonyms)
'shows' is the link.
Can you help me to learn more?
(Other definitions for card that I've seen before include "Eccentric - stiff paper" , "Piece of stiff paper" , "club perhaps" , "Stiff paper; comb" , "club, for example" .)