Walk half a mile as you crush things underfoot (7)
I believe the answer is:
trample
'you crush things underfoot' is the definition.
I can't judge whether this definition defines the answer.
'walk half a mile' is the wordplay.
'walk' becomes 'tramp' (tramp can mean to walk around).
'half a' indicates taking half.
'mile' with half the letters taken is 'le'.
'tramp'+'le'='TRAMPLE'
'as' acts as a link.
Can you help me to learn more?
(Other definitions for trample that I've seen before include "Walk heavily or roughly" , "Flatten" , "Tread roughly underfoot" , "One of the Simpsons" , "Heedlessly tread down" .)