Definition of Lacertian:

part of speech: adjective

Pert. to the family of lizards.

Usage examples:

• What the Protamniota were like, I do not suppose any one is in a position to say, but I cannot think that the thoroughly Lacertian Protorosaurus had anything to do with them. Thomas Henry Huxley in "Critiques and Addresses".

• Although the head is wanting in all the examples yet found, they clearly belong to the Lacertian order, and are therefore of a higher grade than any other vertebrate animal hitherto found fossil in a Palaeozoic rock. Sir Charles Lyell in "The Student's Elements of Geology".