Good to have academic dress (4)
I believe the answer is:
gown
'academic dress' is the definition.
'gown' can be an answer for 'dress' (gown is a kind of dress). I'm not sure about the 'academic' bit.
'good to have' is the wordplay.
'good' becomes 'g' (abbreviation).
'to have' becomes 'own' (to have something is to own it).
'g'+'own'='GOWN'
Can you help me to learn more?
(Other definitions for gown that I've seen before include "Academic or formal dress" , "Loose flowing garment for woman or judge" , "Loose dress or robe" , "Ball dress" , "Academic robe" .)