earlier written -logie, an ending occurring originally in words adapted from Gr. words in -λογία (the earliest examples, e.g., theology, having come through F. -logie, med.L. -logia). These Gr. words for the most part are parasynthetic derivatives; in some instances the terminal element is λόγος word, discourse (e.g., in τετραλογία tetralogy, τριλογία trilogy); more commonly it is the root λογ- (ablaut-variant of λεγ-, λέγειν to speak: cf. LOGOS). In the latter case, the sbs. in λογία usually denote the character, action or department of knowledge proper to the person who is described by an adj. or sb. in -λόγος, meaning either ‘(one) who speaks (in a certain way),’ or ‘(one) who treats of (a certain subject).’ Hence the derivatives in -λογία are of two classes, (1) those that have the sense of ‘saying or speaking,’ examples of which are the words anglicized as battology, brachylogy, cacology, dittology, eulogy, palillogy, tautology; and (2) names of sciences or departments of study. As the words of the last-mentioned class have always a sb. for their first element, and o is the combining vowel of all declensions of Gr. sbs., the ending of these compounds is in actual use always -ολογία, becoming -OLOGY in Eng. The names of sciences with this ending are very numerous: some represent words already formed in Gr., as theology, astrology; many represent formations that might legitimately have existed in Gr., as geology, zoology, psychology; others are of hybrid composition, as sociology, terminology, insectology. The modern formations in -logy follow the analogy of Gr. formations in having o as the combining vowel; exceptions are petralogy (an incorrect form which some writers prefer to petrology because it shows the derivation from τέτρα rock, not from τέτρος stone) and mineralogy (F. minéralogie) which may be viewed as a contraction for *mineralology. The suffix -ology is freely used in the formation of humorous nonce-wds., some of which are illustrated below. All the modern formations in -logy may be said to imply correlative formations in -LOGICAL and -LOGIST; in the case of some of the older words, the related personal designation ends in -LOGER or -LOGIAN. (Cf. -LOGUE.) Hence Logy nonce-wd. = OLOGY.
1820. W. Buckland, in Mrs. Gordon, Life (1894), 40. Having allowed myself time to attend to nothing there but my undergroundology.
1837. Fraser’s Mag., XV. 360. Hats were of scientific importance in his estimation, he had originated a system of hatology.
1853. (title) Chapology, or Hints about Hats.
1856. J. Young, Demonol., IV. iii. 372. The many Logies and Isms that have lately come into vogue.
1891. T. Hardy, Tess (1900), 49/1. What are called advanced ideas are really in great part but … a more accurate expression, by words in logy and ism, of sensations which men and women have vaguely grasped for centuries.
