Cancel visit on holiday (4,3)
I believe the answer is:
call off
'cancel' is the definition.
(I've seen this before)
'visit on holiday' is the wordplay.
'visit' becomes 'call' ('call' can be a synonym of 'visit').
'on holiday' becomes 'off' (I've seen this before).
'call'+'off'='CALL OFF'
(Other definitions for call off that I've seen before include "Stop" , "Cancel as with match - shout it?" , "Order to desist" , "Cancel or terminate - shout away" , "Abandon" .)