testudo

[ te-stoo-doh, -styoo- ]
/ tɛˈstu doʊ, -ˈstyu- /

noun, plural tes·tu·di·nes [te-stood-n-eez, -styood-] /tɛˈstud nˌiz, -ˈstyud-/.

(among the ancient Romans) a movable shelter with a strong and usually fireproof arched roof, used for protection of soldiers in siege operations.
a shelter formed by overlapping oblong shields, held by soldiers above their heads.

Origin of testudo

1350–1400 for earlier sense “tumor”; 1600–10 for def 1; Middle English < Latin testūdō tortoise, tortoise shell, siege engine; akin to test2

British Dictionary definitions for testudines

testudo
/ (tɛˈstjuːdəʊ) /

noun plural -dines (-dɪˌniːz)

a form of shelter used by the ancient Roman Army for protection against attack from above, consisting either of a mobile arched structure or of overlapping shields held by the soldiers over their heads

Word Origin for testudo

C17: from Latin: a tortoise, from testa a shell