sermō

Lingua denotes the speech of any, even the most uncultivated people, gens or natio, in as far as they possess proper words to express their notions; whereas sermo, only the speech of a cultivated people, populus, in as far as it is adapted for the expression of connected thoughts. Lingua is, like the tongue, born with us, and refers more to the mere gift of speech; sermo requires voluntary activity, and involves the rules of grammar and of style. Cic. Fin. i. 3, 10. Sæpe disserui Latinam linguam non modo non inopem, sed locupletiorem etiam esse quam Græcam: comp. with Off. i. 31. Sermone debemus uti eo, qui notus est nobis. (iv. 22.)

1. Sermo (εἰρόμενος) denotes a conversation accidentally arising, or at least carried on without any fixed and serious purpose; whereas colloquium, generally a conversation agreed upon for a particular purpose, like a conference. 2. Sermo is a natural mode of speaking; oratio, a speech premeditated and prepared according to the rules of art. The sermo arises when, in ordinary life, an individual speaks longer than usual, and continues speaking, and is accidentally not interrupted; the oratio has a definite extent with an observable beginning, middle, and end, and in it the speaker calculates upon not being interrupted. In the sermo, the language of ordinary life predominates, whether in prose or verse, as in the comic poets, and in the Sermones of Horace; whereas in the oratio the language is select, and in conformity to the rules of rhetoric. Cic. Orat. 16. Mollis est oratio philosophorum et umbratilis . . . Itaque sermo potius quam oratio dicitur. Tac. Hist. i. 19. Apud senatum non comptior Galbæ, non longior . . . sermo; Pisonis comis oratio. (iv. 23.)