promammal

noun

pro·​mammal

(ˈ)prō+

1

: an extinct reptile exhibiting definite mammalian characteristics

especially : a synapsid reptile

2

a

: a primitive mammal (as a platypus) not exhibiting all the characteristics of the group

b

: one of the Protomammalia

Word History

Etymology

pro- entry 1 + mammal

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