The Collaborative International Dictionary
Quadrumana \Quad*ru"ma*na\, n. pl. [NL. See Quadrumane.] (Zo["o]l.) A division of the Primates comprising the apes and monkeys; -- so called because the hind foot is usually prehensile, and the great toe opposable somewhat like a thumb. Formerly the Quadrumana were considered an order distinct from the Bimana, which last included man alone.
Wikipedia
Quadrumana and Bimana form an obsolete division of the primates: the Quadrumana are primates with four hands (two attached to the arms and two attached to the legs), and the Bimana are those with two hands and two feet. The attempted division of "Quadrumana" from "Bimana" forms a stage in the long campaign to find a secure way of distinguishing Homo sapiens from the rest of the great apes, a distinction that was culturally essential.
Quadrumana is Latin for "four-handed ones", which is a term used for apes since they do not have feet attached to their legs as humans do, but instead have hands, as both pairs of hands look almost alike (with the exception of the orangutan, whose hands look exactly the same) and operate exactly like hands.
Bimana is Latin for "two-handed ones", which is a term used for humans, as humans have only two hands, but have two feet which apes do not.
The division was proposed by Johann Friedrich Blumenbach in the first edition of his Manual of Natural History (1779) and taken up by other naturalists, most notably Georges Cuvier. Some elevated the distinction to the level of an order.
However, the many affinities between humans and other primates – and especially the great apes – made it clear that the distinction made no scientific sense. In 1863, however, Thomas Henry Huxley in his Evidence as to Man's Place in Nature demonstrated that the higher apes might fairly be included in Bimana. Charles Darwin wrote, in The Descent of Man (1871):
Usage examples of "quadrumana".
As to the health of the members of the colony, bipeds or bimana, quadrumana or quadrupeds, it left nothing to be desired.
It was well worth while, besides, to turn Prospect Heights into a kitchen-garden, defended by its deep belt of creeks, and to remove them to the meadows, which had no need of protection against the depredations of quadrumana and quadrapeds.
The rest, throwing themselves out, were dashed to pieces in their fall, and in a few minutes, so far as they knew, there was not a living quadrumana in Granite House.