testudo [tɛˈstjuːdəʊ, -ˈstuː-] (pl. testudos或testudines -dɪniːz)
(in ancient Rome) a screen on wheels and with an arched roof, used to protect besieging troops (古罗马用于保护攻城军队而装于车轮上的)穹形护顶 ■a protective screen formed by a body of troops holding their shields above their heads in such a way that the shields overlap (由一队士兵举盾围成的)龟甲形连环盾
语源
late Middle English: from Latin, literally 'tortoise', from testa 'tile, shell'