Lookouts (8)
I believe the answer is:
sentries
'lookouts' is the definition.
('sentry' can be a synonym of 'lookout')
This is all the clue.
(Other definitions for sentries that I've seen before include "It sneers at those on watch" , "Lookouts, guards" , "Soldiers on guard duty" , "Sentinels, watches" , "Guards to control entry" .)