A crab is any of various crustaceans with four pairs of legs, a pair of pincers, a flattish shell, and a short, broad abdomen folded under its thorax. Several similar animals, such as the crab louse, or the hermit crab[?], are also called crabs.
A crab is any of various machines used to hoist heavy objects.
... source, however, these electrons are not returned to photosystem II as they would in the analogous cyclic pathway. Instead, the still-excited electrons are transferred to a ...