-ics

A subject of study or branch of knowledge.

French ‑iques, Latin ‑ica, or Greek ‑ika, plural forms.

A large number of such terms exist, of which a few are classics, ethics, genetics, mathematics, obstetrics, politics, and statistics. These are considered to be singular when referring to a subject (behavioural economics is a young science), but can be plural if they are used more generally, or preceded by words such as the, his, such, or their (the classics are hardly read these days). An instance of the subject can sometimes be formed by losing the final letter, so a statistic is a statistical item; see ‑ic.