Stride briskly collecting rubbish (6)
I believe the answer is:
debris
'rubbish' is the definition.
(I know that debris is a type of rubbish)
'stride briskly collecting' is the wordplay.
'collecting' says the answer is hidden in the clue.
'DEBRIS' can be found hidden inside 'stride briskly'.
(Other definitions for debris that I've seen before include "Broken remains" , "'Ruins, rubble (6)'" , "Brides with pieces of rubble" , "aftermath of wild reception?" , "Rubble, detritus" .)