What Does “Agha” Mean in Irish Placenames?

Towns and cities with Agha

Monaghan · Muineachán · County Monaghan
'place of little thickets' or little hills
Donaghadee · Domhnach Daoi · County Down
Two possible meanings are given: 'church of Daoi', after an otherwise unrecorded saint, or 'church of the motte'
Dunshaughlin · Dún Seachlainn · County Meath
The fort of Seachlainn, or locally Domhnach Seachnaill, St Seachnall's church; the article says the town is named for St Seachnall, and Joyce gives Domhnach-Sechnaill, the church of St Sechnall
Ballaghaderreen · Bealach an Doirín · County Roscommon
The way of the little oak grove

Quick answers

What does Agha mean in Irish place names?

Field: it is the Irish achadh. It is written Agha, Augh, Agh in English spellings of Irish names.

How is Agha spelled in Irish?

achadh. English spellings of the same word include Agha, Augh, Agh, because the names were written down by ear.

Which towns have Agha in their name?

Monaghan (Muineachán), Donaghadee (Domhnach Daoi), Dunshaughlin (Dún Seachlainn), Ballaghaderreen (Bealach an Doirín).