suffix of sbs. [a branch of the wider suffix -CY, a virtual compound of -Y, ME. -ye, -ie, Fr. -ie, L. -ia, with preceding t or c, though the L. was rather -ci + a, -ti + a, than -c + ia, -t + ia.] 1. ad. L. -āci-a, forming sbs. of quality on adjs. in -āci-, as fall- deceive, fall-āci- deceitful, fallāci-a deceitfulness, fallacy; so contumacy, efficacy. The corresponding Fr. words are in -ace; -acy is entirely of Eng. formation, analogous to other endings in -Y, for L. -ia; cf. -NCE and -NCY. A parallel suffix is the more frequent -ACI-TY, as in rapacity; and an equivalent to both -ACIOUS-NESS, as in rapaciousness, fallaciousness. 2. representing or imitating L. -āt-i-a, in med. L. often written -ācia, OFr. -acie, forming sbs. of quality, state, or condition, on nouns in -āt- (nom. -ās), being only a section of the sbs. in -tia from nouns in -t-, -ti-, in which the suffix was properly -a, and the i either part of the stem or connective, cf. inerti-a, infant(i-a, mīlit-i-a. Thus: late L. abbāt-, abbāt-ia abbacy, L. prīmāt-, med.L. prīmātia, Fr. primatie, primacy; L. optimāt., Fr. optimatie, optimacy; L. diplōmat-, Fr. diplomatie, diplomacy; late L. pāpāt- (nom. pāpās = pāpa) Anglo-L. pāpātia (= pāpātus) papacy. Imitation of primacy has given supremacy, Fr. suprématie. 3. repr. med.L. -ātia, forming sbs. of state on nouns in -āt-us; cf. cl. L. -tia from -tus, in grāt-ia, minūt-ia, molest-ia, etc. Thus, (perhaps due in part to form-association with abbātia, prīmātia, pāpātia,) med.L. advocātia, prælātia, lēgātia, advocacy, prelacy, legacy, f. advocātus, prælāt-us, legāt-us; whence without any L. precedent, curacy, confederacy, magistracy, on other words in L. -ātus or Eng. -ate. Also extended to adjs., as accurate, alternate, whence accuracy, alternacy = accurate-ness, alternate-ness. So degeneracy, delicacy, effeminacy, intimacy, intricacy, inveteracy, legitimacy, obstinacy, privacy, profligacy, subordinacy, etc. The cl. L. forms answering to these, when f. pples., were in -ātiō(nem), as accūrātio, obstinātio, prælātio, lēgātio: hence -ātio has been englished as -acy in other words where no Eng. -ate exists, as conspīrātio, procūrātio conspiracy, procuracy. Of others the proper L. form was -ātus (4th decl.) as pāpātus, magistrātus: hence in other words this has given Eng. -acy, as episcopātus, cælibātus, episcopacy, celibacy. Lunacy has been formed to match lunatic, after the relation of prelacy, diplomacy, to prelatic, diplomatic. It thus appears that -acy f. -ātus, -ate, is almost entirely analogical and of Eng. formation. 4. repr. Gr. sbs. of state in -άτεια, f. nouns in -ατης, or vbs. in -ατεύειν; as πειρᾱτής, L. pīrāta, pirate, πειρατεύ-ειν to pirate, πειράτεια, Anglo-L. pīrātīa, piracy, identified with L. forms like legātĭa legacy above. Also in -cracy, Gr. sbs. in -κρατία, L. -cratia, Fr. -cratie, as aristocracy; see -CRACY.