A Grammatical Dictionary of Botanical Latin

Crab: astacus,-i(s.m.II), q.v., abl.sg. astaco = Gk. astakos: “a kind of crab” (Lewis & Short); “the lobster or crayfish” (Glare); cancer, gen. sg. cancri (s.m.II), acc. sg. cancrum, dat. & abl. sg. cancro, nom. pl. cancri, gen. pl. cancrorum, acc. pl. cancros, dat. & abl. pl. cancris; for notes on declension, see ‘cancer, gen. sg. cancri.’

Greek: karkinos (s.m.II): a crab, = L. cancer; “the Crab, as a sign in the zodiac” (Liddell & Scott).

NOTE: special declension forms of cancer, gen.sg. cancri; q.v.

- odore cancri, with the odor of a crab. ?of a cancer?

- Corallina Astaci corniculorum aemula (Tourn.), Corallina resembling [+ gen.] the little horns of a crab.

"Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) (Greek: βραχύς, romanized: brachys = short, + οὐρά / οura = tail), usually hidden entirely under the thorax" [Wikipedia, "Crab" Sept 2020].