Breathes hard (5)
'breathes hard' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pants that I've seen before include "Useless (slang) - gasps" , "Briefs" , "American trousers" , "Bloomers" , "Puffs, gasps" .)
(Other definitions for blows that I've seen before include "See 5" , "See 1" , "Impacts" , "Powerful strokes with fist or weapon" , "Gusts - squanders" .)