Translation according to P. W. Joyce:
Meanus in Galway, Kerry and Limerick ; Mianus, a mine. S is here added to the root-word mian (vol. ii. p. 13).
S. This is a usual termination for abstract nouns; as for instance in aeibhneas [eevnas], delight, from aeibhinn [eevin], delightful; maitheas [mahas], goodness, from maith [mah], good. It occurs sufficiently often in local names (with a vowel sound preceding when necessary - p. 3) to deserve rank as a distinct termination; but in the greater number of those names in which I have found it, I am unable to perceive that it indicates abstract quality. Often it seems to have something of a collective meaning like r; but in many cases it appears to have been used for no definite purpose at all. Bearna is the usual word for a gap; but we have the authority of Irish MSS. for another form of the word, namely bearnas, which appears to differ in nowise from the first; and the two words corcach and corcas, both of which are in constant use to signify a marsh, are equally identical in meaning. Here, however, the conclusion we ought to draw is, that this letter as a termination had once a meaning which it has lost. Pullis is the name of a townland in the parish of Donagh, county Monaghan, near Glasslough; and it means a place full of holes, from poll, a hole. Leamh [lav] is the elm tree; and Cloonlavis in the parish of Knock in Mayo, is the cloon or meadow of the elms. Magherascouse is the name of a place near Comber in Down, which very well conveys the sound of Machaire-sceamhais, the field of the polybody, or wall fern, the Irish name for this herb being sceamh [scav, scow].