o, ā (cethair) ord. num. fourth . Later uninflected ( GOI 230 ): quarta .i. cethramadh, Ir. Gl. 142 . cethirmat, Ériu lviii 97, 99-101 (Computus Einsidlensis) . in ch.¤ accuis, Ml. 118d18 . a buith far c.¤ `that it is of the fourth (declension)', Sg. 106b19 . ainm inna cethramthæ dúalchæ, ZCP iii 26.15 . 'sinchethramaid essergi, SR 8241 . iar forbu na cethraime dec, PH 5108 . iár c.¤ laithiu gl. quartana die, Thes. i 497.13 (Ardm.). hisinc.¤ ceniul na sulbaire, Hib. Min. 13.440 . in c.¤ bliadain `every fourth year', Laws iv 168.4 . c.¤ gnim the fourth piece of work, SR 4209 . cosin cetramad ndorus, LU 2105 ( FA 17 ). c.¤ déc sin ésci 14th, PH 5070 . do rér an cethramhadh I. Pápa, RSClára 112b . do'n cheathramhadh hAithne, Donlevy 80.16 . In `completive' sense (see Lochlann iii 287 ff. ): tri hesbada . . . ┐ issí seo in c.¤ esbaid, Acall. 5277 . na trī cūigidh . . . ┐ an cethramadh cōiged, ML² 1388 . One of four: in c.¤ nech is ferr `one of the four best men', RC xxiii 424 § 44 . an c.¤ fer . . . fuair bás, Acall. 3589 (see Gloss.). in c.¤ mog fichet one of the 24 slaves, Dinds. 69 .