Obtained oddly deficient belt (4)
I believe the answer is:
band
'belt' is the definition.
(thesaurus)
'obtained oddly deficient' is the wordplay.
'oddly deficient' indicates alternate letters (letters in odd-numbered positions removed).
The alternating letters of 'obtained' are 'BAND'.
(Other definitions for band that I've seen before include "Zone; group" , "Musicians - circle" , "Ring or musical group (4)" , "Belt; group of musicians" , "Players" .)