Sentence:  The sentry didn't answer. Taking a closer look at him I realised he wasn't a real sentry but a <WSD>cut-out</WSD> sentry, guarding not a real but a <WSD>cut-out</WSD> border. 
Meaning of the word marked with <WSD> tags:  A free-standing, rigid print (usually life-sized), often displayed for promotional purposes; a standee.