Bikini maybe excessively abbreviated all around (5)
I believe the answer is:
atoll
'bikini' is the definition.
(Bikini Atoll is an example)
'excessively abbreviated all around' is the wordplay.
'excessively' becomes 'too' (to too great a degree).
'abbreviated' means to remove the last letter (the word is shortened or abbreviated).
'around' is an insertion indicator.
'too' with its last letter taken away is 'to'.
'to' put into 'all' is 'ATOLL'.
'maybe' is the link.
(Other definitions for atoll that I've seen before include "Coral island surrounding a lagoon" , "Allot (anag.)" , "Bikini, perhaps" , "Key" , "Bikini for one" .)