Bunch of stars addicted to drinking port (5)
I believe the answer is:
orion
'bunch of stars' is the definition.
'orion' can be an answer for 'stars' (Orion is a constellation). I am not certain of the 'bunch of' bit.
'addicted to drinking port' is the wordplay.
'addicted to' becomes 'on' (on drugs).
'drinking' is an insertion indicator (inserted letters are consumed or drunk).
'port' becomes 'rio' (Rio de Janeiro is a port).
'on' going around 'rio' is 'ORION'.
Can you help me to learn more?
(Other definitions for orion that I've seen before include "Mythical great hunter" , "Great hunter of Greek legend and a constellation" , "One who would hunt" , "Constellation with seven bright stars" , "Constellation that includes Betelgeuse" .)