Translation according to P. W. Joyce:
Ard, a height (or as an adjective high), entering so frequently into Irish names, has been already discussed in vol. i. p. 385 [reproduced below]. Other combinations will be examined here.
Ard is sometimes a noun meaning a height or hill, and sometimes an adjective, signifying high: cognate with Lat. Arduus. In both senses it enters extensively into Irish nomenclature; it forms the beginning of about 650 townland names; and there are at least as many more that contain it otherwise combined. There is a little town in Waterford, and about twenty-six townlands in different counties, called Ardmore, great height; but only two bear the correlative name, Ardbeg, little height. Ardglass in Down is called Ard-glas by the Four Masters, i.e. green height; which is also a usual townland name; and there are many places scattered over the country, called Ardkeen, that is, Ard-caein, beautiful height. Arderin in the Queen's County is the highest of the Slieve Bloom range; and the inhabitants of the great central plain who gave it the name, signifying the height of Ireland, unaccustomes as they were to the view of high mountains, evidently believed it to be one of the principal elevations in the country. When ard is followed by tighe [tee], a house the final d is usually omitted; as in Artiferrall in Antrim, Ard-tighe-Fearghaill, the height of Farrell's house; Artimacormick near Ballintoy, same county, the height of Mac Cormack's house, etc. This word has two diminutives, airdin and ardán [ardeen, ardaun]; the former is not much in use, but it gives name to some places in Cork and Kerry, called Ardeen, and it forms a part of a few other names. The latter, under the different forms Ardan, Ardane, and Ardaun, all meaning little height or hillock, is by itself the name of several places in the midland counties; and it helps to form many others, such as Ardanreagh in Limerick, grey hillock; and Killinardan near Tallaght in Dublin, the church or wood of the little height.