Translation according to P. W. Joyce:
Killeighter in Galway and Kildare; Coill-iochtair, lower wood. See Iochdar (a noun) in vol. ii. p. 442.
Lower. The opposite term to uachdar is iochdar, which signifies lower; and this and the adjective form íochdarach, appear in anglicised names in such forms as eighter, eighteragh, etra, etc., which are illustrated in Carroweighter in Roscommon, lower quarter-land; in Broighter on the railway line between Magillian and Derry, broghiochdar, lower brugh or fort; and in Moyeightragh near Killarney, lower plain. In the parish of Desertoghill in Derry, there are two adjacent townlands called Moyletra Kill and Moyletra Toy. Moyletra signifies lower mael or hill; kill is "church"; toy is tuath, a layman, or belonging to the laity; and these two distinguishing terms indicate that one of the townlands belonged to some church, and the other to a lay proprietor. Very often when a townland was divided into two, the parts were distinguished by the terms oughter and eighter, upper and lower, or by the anglicised adjective forms otra and etra, or otre and etre; which is seen in Moy Etra and Moy Otra in the parish of Clontibret in Monaghan, lower Moy (plain) and upper Moy; as well as in many other names.