Cancel directions to entrance (6)
I believe the answer is:
negate
'cancel' is the definition.
(I've seen this before)
'directions to entrance' is the wordplay.
'directions' becomes 'ne' (I've seen this in other clues).
'to entrance' becomes 'gate' (type of entrance).
'ne'+'gate'='NEGATE'
(Other definitions for negate that I've seen before include "Deny the truth of" , "Countermand" , "Age ten (anag)" , "Contradict" , "Cause to have no effect" .)