any mammal in the subclass Theria, which includes marsupials
adjective
2.
of or relating to the mammal subclass Theria, which includes marsupials
therian in American English
(ˈθɪəriən)
adjective
1. (in some classification systems)
belonging or pertaining to the group Theria, comprising the marsupial and placental mammals and their extinct ancestors
noun
2.
a therian animal
Word origin
[‹ NL Theri(a) name of the group (‹ Gk thēría, pl. of thēríon wild beast) + -an]-an is a suffix occurring originally in adjectives borrowed from Latin, formed from nounsdenoting places (Roman; urban) or persons (Augustan), and now productively forming English adjectives by extension of the Latin pattern.Attached to geographical names, it denotes provenance or membership (American; Chicagoan), the latter sense now extended to membership in social classes, religious denominations,etc., in adjectives formed from various kinds of noun bases (Episcopalian; pedestrian; Puritan; Republican) and membership in zoological taxa (acanthocephalan; crustacean). Attached to personal names, it has the additional senses “contemporary with” (Elizabethan; Jacobean) or “proponent of” (Hegelian; Freudian) the person specified by the noun base. It also occurs in a set of personal nouns,mainly loanwords from French, denoting one who engages in, practices, or works withthe referent of the base noun (comedian; grammarian; historian; theologian)