outgroup noun 2verb 1forms 3 noun2 •The group of people who do not belong to one's own social group. •In cladistics, all the taxa included in a study that do not belong to the ingroup that is of immediate interest.A cladistic analysis of 45 ingroup and two outgroup taxa was performed on the basis of 134 characters. — 2009 verb1 •To form an outgroup. formsoutgrouped · outgrouping · outgroups
