I. “+ adjective
Etymology: sub- + human
: less than human: as
a. : failing to attain the level (as of morality or intelligence) associated with normal human beings
a subhuman child
treating the natives as subhuman
b. : unsuitable to or unfit for human beings
subhuman conditions of life
a subhuman spectacle
c. : approaching that normal to man
a dog with subhuman intelligence
d. : of, relating to, or belonging to an infrahuman group
the subhuman primates
the army ant … presents the most complex instance of organized mass behavior … in any subhuman animal — T.C.Schneirla & Gerard Piel
II. noun
: a subhuman individual ; especially : a person so deficient in ordinary human characteristics as to seem a member of a different species
such moronic subhumans — Time