-cysuffix

suffix of nouns, originating in Latin -cia, -tia, Greek -κια, -κεια, -τια, -τεια, in which the abstract ending -ia (-y suffix³) follows another formative element. Occurring chiefly in the combined forms -acy suffix, -ancy suffix, -ency suffix, -cracy comb. form, -mancy comb. form. Also in prophecy, Greek προϕητεία, < προϕήτης prophet; policy, Greek πολιτεία, < πολίτης citizen, -polite, secrecy < secret. In words in -acy from Latin -ātia, and those in -ncy, the c represents an original t before i, which became c often in late Latin and in French, e.g. Latin infantia, late Latin also infancia, French enfance, infancy. Hence abstract nouns in -ncy arise out of adjectives or nouns in -nt, expressing the quality of an adjective (fluent, fluency), or the estate or position of an agent or officer (agent, agency). But by proximity of sound, -cy is extended from nouns in -nt to some in -n, e.g. chaplain-cy, captain-cy, alderman-cy (after incumbency, lieutenancy, adjutancy), and -cy being thus treated as an independent suffix = -ship suffix, is extended to other words as colonel-cy, and is even added to words in -t (instead of being substituted for the -t), as in bankrupt-cy (for which the regular etymological form is bankrupcy), idiot-cy variant of idiocy n. (Greek ἰδιωτεία), baronet-cy, brevet-cy, cornet-cy (as against secret, secrecy).