Sentence:  The target or <WSD>buckler</WSD> was carried by the heavy armed foot, it answered to the scutum of the Romans; its form was sometimes that of a rectangular parallelogram, but more commonly had it's bottom rounded off; it was generally convex, being curved in it's breadth. 
Meaning of the word marked with <WSD> tags:  A shield resembling the Roman scutum. In modern usage, a smaller variety of shield is usually implied by this term.