Run found in stockings on the Sabbath nags (6)
I believe the answer is:
horses
'nags' is the definition.
'run found in stockings on the sabbath' is the wordplay.
'run' becomes 'r' (cricket abbreviation**).
'found in' means one lot of letters goes inside another.
'stockings' becomes 'hose' (I've seen this before).
'on' is a charade indicator (letters next to each other).
'the sabbath' becomes 's'.
'r' going inside 'hose' is 'horse'.
'horse'+'s'='HORSES'
(Other definitions for horses that I've seen before include "Equine beasts" , "Hoofed mammals (which go with 19 4)" , "Eg, stallions" , "Equine animals" , "Domesticated animals" .)