X is a symbol for ks: see Groups, § [79], Ks.
Y, representing Latin dy, g´, gy, j, and z (cf. § [55], G, Y; § [57], Z) had a varied development.
(1) When it became contiguous to a following consonant (§§ [45], [49]) it changed to i: adjutāre ＞ ayudāre ＞ ay’dar ＞ aidar, medietātem ＞ meitat; cōgitāre ＞ cüidar, frīgĕre ＞ frire, lĕgĕre ＞ lęyre, propagĭnem ＞ probaina, rĭgĭda ＞ rẹida, ✱tragĕre ＞ traire; bajŭlus ＞ bailes.
(2) When it remained intervocalic, it became dž in most of the territory, but in the northeast and parts of the north it was not changed:[54] audiam ＞ auia, in-ŏdiare ＞ enoiar, invĭdia ＞ envẹia, invĭdiōsus ＞ enveiọs enveyọs, ✱gladia ＞ glaya, mediānum ＞ meian, ✱pŏdiāre ＞ poiar, radiāre ＞ raiar, sordĭdior ＞ sordẹier, vĭdeat ＞ vẹia; fragĭlem ＞ fragel; ✱exagiāre ＞ assatiar essaiar essayar, corrĭgia ＞ corrẹia corrẹya, fagea ＞ faia faya, regiōnem ＞ reiọ; dīe Jŏvís ＞ diiǫus, major ＞ maier, pĕjor ＞ pięier, pejōrem ＞ peiọr, trŏja ＞ trǫia; baptizāre ＞ bateiar. For a dž or a y that became final or contiguous to final s, see § [63], (1), (2): audio ＞ auch, in ŏdio ＞ enuęg (plural enuętz enuęg) enǫi, gaudium ＞ gauch, gladium ＞ glai, mĕdium ＞ męg męi, hŏdie ＞ ǫi, pŏdium ＞ puęg pǫi, radium ＞ rai; fŭgit ＞ füg füi, grĕgem ＞ gręy, lēgem ＞ lẹg (pl. lẹitz) lẹi, lĕgit ＞ lięg, magis mais,[55] rēgem ＞ rẹi, exagium ＞ essai; pĕjus ＞ pięis.
(3) Before accented e or i, y disappeared (doubtless in Vulgar Latin: § [55], G), except in some western dialects, where it became dž: vagīna ＞ guaīna, ✱legīre (= lĕgĕre) ＞ legir,[56] magĭster ＞ maẹstre maiẹstre magẹstre, ✱pagē(n)sis ＞ paẹs pagẹs, regīna ＞ reïna, sagĭtta ＞ saẹta saiẹta sagẹta.
1. Detz ditz ＞ dĭgĭtus are irregular and unexplained. The word is irregular in some other Romance languages, notably in Italian. Cf. Gröber’s Grundriss, I, p. 507.
2. Glavi, beside glai (and learned glazi) ＜ gladium, is supposed by some to show the influence of Celtic cládibo. Cf. Körting; also H. Schuchardt, Zs., XXV, 345.
3. Messér seems to be a contraction (due to proclitic use) of ✱messeyer = mes, ‘my’, + ✱seyer? ＜ ✱sĕyor = sĕnior (cf. A. Lindström, L’analogie dans la déclinaison des substantifs latins en Gaule, 1897-8, pp. 292-3).
4. In purely learned words, di, g, gi, z are retained, the g being pronounced presumably as dž, the z as z: odi, fragil, regio, canonizar.