Thermae be applied to those magnificent edifices which grew up under the empire, in place of the simple balneae of the republic, and which comprised within their range of buildings all the appurtenances belonging to the Greek gymnasia, as well as a regular establishment appropriated for bathing. Writers, however, use these terms without distinction. Thus the baths erected by Claudius Etruscus, the freedman of the Emperor Claudius, are styled by Statius "balnea", and by Martial "Etrusci thermulae". In an epigram by "Martial"—"subice balneum thermis"—the terms are not applied to the whole building, but to two different chambers in the same edifice.
Thermae singular number, were the public baths. But this accuracy of diction is neglected by many of the subsequent writers, and particularly by the poets, amongst whom "balnea" is not uncommonly used in the plural number to signify the public baths, since the word "balneae" could not be introduced in a hexameter verse. Pliny also, in the same sentence, makes use of the neuter plural "balnea" for public, and of "balneum" for a private bath. "Thermae" (Greek: , "Thermai", "hot springs, hot baths", from the Greek adjective "thermos", "hot") meant properly warm springs, or baths of warm water; but came to