Tear off at speed (4)
I believe the answer is:
rate
'speed' is the definition.
(both can mean pace)
'tear off' is the wordplay.
'off' indicates an anagram.
'tear' with letters rearranged gives 'RATE'.
'at' is the link.
(Other definitions for rate that I've seen before include "Be worthy of; speed" , "Charge per unit" , "Relative speed (of progress)" , "Adjudge" , "Capital of the Philippines" .)