Guard (6)

'guard' is the definition.
(I know that escort is a type of security guard)
This is all the clue.
(Other definitions for escort that I've seen before include "Social companion or military guard" , "Provide company - car - guard" , "Companion, perhaps for protection" , "restraint" , "guide" .)
'guard' is the definition.
(I know that sentry is a type of security guard)
This is all the clue.
(Other definitions for sentry that I've seen before include "Soldier posted to keep watch" , "Sentinel, watch" , "Guard on watch" , "One keeps watch" , "Look-out, guard" .)
'guard' is the definition.
(defend can mean to guard or protect)
This is all the clue.
(Other definitions for defend that I've seen before include "Protect - guard" , "Stand up for" , "Safeguard" , "Justify" , "Help or protect against attack" .)
'guard' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for captor that I've seen before include "One who takes a prisoner" , "The one who holds the prisoner" , "One takes prisoners" , "One who imprisons another" , "Top car (anag) -- jailer" .)
'guard' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for defence that I've seen before include "See 12" , "barricade" , "One ministry" , "Protection; justification" , "Justification for some act" .)
'guard' is the definition.
(I know this)
This is all the clue.
(Other definitions for protect that I've seen before include "Keep safe" , "Shield from danger" , "Keep from harm" , "Guard" , "Safeguard" .)