Bits of cold strange US rubbish (6)
I believe the answer is:
crumbs
'bits' is the definition.
(I know this)
'cold strange us rubbish' is the wordplay.
'cold' becomes 'c' (eg on taps).
'strange' becomes 'rum' (similar in meaning).
'us rubbish' becomes 'BS' (be means bullshit).
'c'+'rum'+'bs'='CRUMBS'
'of' acts as a link.
(Other definitions for crumbs that I've seen before include "Surprised expression; bread fragments" , "not much of a bloomer!" , "Very little to eat -- goodness gracious me!" , "Small bread particles" , "By heck! -all that's left of the cake?" .)