a suffix of nouns that denote a body of facts, knowledge, principles, etc., usually corresponding to adjectives ending in -ic or -ical: ethics; physics; politics; tactics.
[ pl. of -IC, repr. L -ica ( -ika, neut. pl. of -ikos ), as in rhetórica (pl.) rhetoric book ]
Usage . Nouns ending in -ICS that name fields of study, sciences, arts, professions, or the like are usually not preceded by an article and are used with a singular verb: Acoustics (the science) deals with sound. Politics (the art of government) fascinates me. In certain uses, often when preceded by a determiner like the, his, her, or their, most of these nouns can take a plural verb: The acoustics (the sound-reflecting qualities) of the hall are splendid. Their politics (political opinions) have antagonized everyone.