Stay outside and check procedure (6)
I believe the answer is:
system
'procedure' is the definition.
(a procedure is a system or practice)
'stay outside and check' is the wordplay.
'outside' says to hollow out the word (remove centre letters).
'and' means one lot of letters go next to another.
'check' becomes 'stem' (both can mean to control or stop).
'stay' with its centre taken out is 'sy'.
'sy'+'stem'='SYSTEM'
(Other definitions for system that I've seen before include "Method (for betting?)" , "coherent plan" , "Arrangement of units that function together" , "Ordered scheme" , "Organisational method" .)