Siren finding a new role with a Hawaiian garland (7)
I believe the answer is:
lorelei
'siren' is the definition.
(I know that Lorelei is a siren)
'a new role with a hawaiian garland' is the wordplay.
'a new' is an anagram indicator.
'with' means one lot of letters go next to another.
'a hawaiian garland' becomes 'lei' (I've seen this before).
'role' anagrammed gives 'lore'.
'lore'+'lei'='LORELEI'
'finding' is the link.
(Other definitions for lorelei that I've seen before include "Enchanting singer" , "Twenty down siren nymph; lie role (anag.)" , "High rock in the Rhine gorge" , "Legendary German rock singer" , "Legendary siren who lured Rhine boatmen to destruction" .)