Strange bulge in bit of brass (5)
I believe the answer is:
bugle
'bit of brass' is the definition.
(I've seen this before)
'strange bulge' is the wordplay.
'strange' is an anagram indicator.
'bulge' is an anagram of 'BUGLE'.
'in' is the link.
(Other definitions for bugle that I've seen before include "Horn" , "one may have blown it!" , "Instrument used for military signals" , "Brass instrument; plant" , "costume ornament?" .)