-aí

From earlier -aidhe, originally the Old Irish accusative and vocative plural ending of d-stem nouns. For example Old Irish arae, plural arada.

• -aidhe (obsolete)
• -í (slender form)
• -idhe (obsolete slender form)

-aí

1. Ending of the plural of certain nouns.

   ‎beannacht (“blessing, greeting”) + ‎-aí → ‎beannachtaí

   ‎gnólacht (“commercial firm”) + ‎-aí → ‎gnólachtaí

From Old Irish -id, from Proto-Celtic *-īti from Proto-Indo-European *-éyeti.

• -aidhe, -oidhe, -uidhe (obsolete)
• -í (slender form)
• -idhe (obsolete slender form)

-aí m

1. Agent suffix

   ‎roth (“wheel”) + ‎-aí → ‎rothaí (“cyclist”)