χελώνα — meaning in English

chelona

English meaning

tortoise noun A land-dwelling reptile with a hard domed shell into which it can withdraw its head and legs for protection.
turtle noun A reptile with a hard protective shell that lives on land, in fresh water, or in the sea.

χελώνα is used for these senses in English:

tortoise Any of various land-dwelling reptiles, of the family Testudinidae (chiefly, North America) or the order Testudines (chiefly, UK, Australia, New Zealand, Ireland, South Africa, India) , whose body is enclosed in a shell (carapace plus plastron). The animal can withdraw its head and four legs partially into the shell, providing some protection from predators.
turtle (zoology, US, Canada) Any land or marine reptile of the order Testudines, characterised by a protective shell enclosing its body. See also tortoise.

noun A reptile with a hard protective shell that lives on land, in fresh water, or in the sea.
verb To flip over onto one's back, especially of a boat capsizing.
verb In gaming, to play very defensively, building up defences rather than attacking.