This place-name is poorly attested and its etymology is uncertain.

The element gate occurs in a number of Wexford toponyms, such as Libgate, OILGATE (par. Edermine) and MOUNTAINGATE (par. Kilmannan). As this toponymic element can sometimes be ultimately of Norse origin (see EPNE i gata), some writers have taken its occurrence in these place-names as evidence of Norse settlement in these areas (Culleton, 1999 p.168; see also Colfer, 2002 pp.20–2). However, this interpretation is highly problematic. The word gate “road” is found in Middle English (see Mid. Eng. Dict. ‘gáte, sb., O.N. gata’) and also in later dialects, including some from southwest England that had close ties to the English dialect of South Wexford (see EDD ‘gate, sb.2... way, path, road’; cf. Ó Muirithe, 1977 pp.41, 48). Therefore the Wexford place-names containing this element can readily be interpreted as having been coined by the Anglo-Norman colonisers and no historical Norse presence need be inferred. Note also that there is no clear corroborative evidence of Norse origin in these place-names, in contrast to other examples in Wexford that are only explicable through derivation from Norse, such as ARKLOW (par. Clonmines) and SELSKAR (par.). In those places Norse settlement can indeed be presumed to have occurred.

It is also possible, given that it is ‘as a rule very difficult to distinguish this [gate, ‘road’] from the ordinary word gate, ‘opening’ ’ (Mawer, 1930 p.28), that Libgate, etc., may have been named with the sense “opening” in mind. Note that the townland of Windgates in north Kildare was recorded as ‘Bearna na gaoithe’ “the gap of the wind” from a local Irish speaker in 1837 (see logainm.ie).

While the second element can be understood to be derived from the language of the English colonists, the origin of the initial element of Libgate is more opaque. The word libe “foolish person” is recorded in the English dialect of this area (see Dolan & Ó Muirithe, 1996 p.26), but the genitive marker (ə)s would normally be expected to follow a noun of this type (see KNOCKSTOWN, par. Killegny). It may be a common noun related to libbet “a rag; a shred, a small fragment” (see EDD libbet), possibly reflecting a tradition of a May-bush or the like. As analysis of the first element is speculative owing to the dearth of historical forms, the Irish form recommended here is a translation using a gaelicised approximation to Lib-.

[Excerpt from Logainmneacha na hÉireann IV: Townland Names of County Wexford, 2016]