Cite this: eDIL s.v. ad- or

Forms: á, ad-, ad-, as-, ad-

prep. prefix used to form compds. See Thurn. Gramm. § 822 ; O'Rahilly, Celtica i 337f. ; Breatnach, Éigse vi 339 . In close compds. remains as ad- before vowels and earlier w (preserved as spirant b): adamrae (amrae), adblam (ad-fo- lam).

The d is assimilated to c, t, g, d, b, s, m: abbrón (brón), Celtica xiii 14.258 . -accobra (adcobra), atrab (ad-treb), acarb, ag(g)arb (ad + garb), atód (ad-do-) apuide, abbuide (ad + buide), aslach (ad-slig), ammus (ad-mess). In the case of m, however, O'Rahilly, loc. cit., regards adm- as the regular development e.g. admass (ad + mass), admat (ad + muinethar), admall (ad + mall), admolaid (ad + m.). Before an original u in follg. syll.: audbirt, idbart, edbart (*ad-uss-bert), aupaid, epaid (ad-buith). Before r, l, n appears as á: áram (ad-rím), fo-álgim (*fo-ad- log-), áinsem (*ad-nessam). As perfective particle, see Thurn. Gramm. § 532 . In pretonic position always ad-: ad-ella, ad- cobra, ad-gládathar, ad-slig, ad-midethar, ad-rími etc. except before t and d, to which the d is assimilated: attá, atá (ad-tá), ataimet (ad-daimet). For the forms with infix. pronouns see Thurn. Gramm. §§ 412, 413 . The fact that ad- and ess- fall together before inf. pronouns has sometimes led to ad- being replaced by as- in pretonic position e.g. as-roilli beside ad- roilli (prototonic -árilli -áirilli). Sometimes ad- replaces in- in pretonic position e.g. ad-cumaing (prototonic -ecmaing), see Thurn. Gramm. § 842 B (1) . Meaning orig. to, towards e.g. ad-gúisi hopes (wishes towards). In many compds. however it has a purely intensive sense e.g. adúath great terror; admór very great; admolaid praises highly. See various compds. below.

See ath-.