Translation according to P. W. Joyce:
Bullaun in several counties, especially in south and west; Bullán, a round spring well in a rock or rocks. Often applied to an artificial cup-like hollow in a rock which generally contains rain water, often used for medicinal purposes with a touch of the super-natural. Related to the English bowl. Bullaunaghin Galway, a place abounding in bullauns or rock-wells. (Termination ach, full of : vol. ii. p. 3.)
Ach, lach, nach, rach, tach, trach, seach. All these postfixes have a collective signification when placed after nouns and generally convey the sense of "full of", "abounding in", much the same as the English postfixes ful, y, and ous. In Irish writings, especially if they be ancient, these terminations are often written ech, lech, etc.; and sometimes, in compliance with a grammatical custom, they are changed to each, leach, etc.; but these changes do not influence the anglicised forms. Ach. This is the most common of all Irish terminations, and its most usual form in anglicised names is agh, which is sounded with a strong guttural by the people, but pronounced ah by those who cannot sound the guttural. Scart means a brake or scrubby place; and Scartagh, the name of a place near Clonakilty in Cork, signifies a place covered with brakes - a bushy spot. From draighen [dreen] the blackthorn or sloebush, we have draighneach, a place abounding in blackthorns; and this again compounded with cill, church, gives Cill-draighnech (so written in the Irish Calendars), the church of the sloe-bushes. It was one of the churches of St. Erinin or Mernoc (died, A. D. 635) who is mentioned by Adamnan in his Life of St. Columba, and who gave name to Inchmarnock and to the two Kilmarnocks in Scotland. This church has left its name on a townland, now called Kildreeenagh, in the parish of Dunleckny in Carlow, near Bagenalstown.