When the anglicisation of Irish placenames began, it was in a piecemeal, unplanned manner, following the dictates of the particular scribe's ear.

There was no set spelling, standardisation being gradual, without any particular pattern of uniformity. It was not until the Index of Townlands was compiled in 1851 that the final definitive "English" versions were determined.

Certain procedures and rules were determined, and generally adhered to. For example, not once anywhere in this compilation was the anglicised element Knock (cnoc, a hillock, a height, a heap, a hoard) ever rendered the more phonetically accurate Nock.

Nor had it been anytime as far back as 1314 when the Calendar of the Justiciary Rolls was compiled between 1308 and 1314. where we found Knock, Knok and Cnok.

Here were John and Stephen Cnok, named from the places from whence they came.

Knock is listed in the Index some 20 times - in counties Armagh, Clare, Cork, Donegal, Down, Dublin, Galway, Offaly, Limerick, Longford, Mayo, Meath, and Wexford. With an English plural, Knocks, it is found naming 10 places in counties Cork, Fermanagh, Leitrim, Mayo, Meath, Roscommon and Wexford. Its diminutive Cnocán, anglicised Knockaun, is found in counties Clare, Galway, Mayo, Sligo and Waterford. And Knockeen found in counties Carlow, Cork Kerry, Limerick, Mayo, Tipperary, Waterford, Wexford and Wicklow.

Liam Price in his Placenames of Co Wicklow gives the Irish as Cnoicín (little hill), a word not found in any dictionary.

However it is found in a Co Kerry song An Cnoicín Gearra Fraoigh noted in Micheál Ó Dubhshláine's book An Baol Dom Tú? Might this have been more accurately rendered garra as found in garra bhuí (greater celandine-Chelidonium majus)?

Líosta Logainmneacha gives Knockeen as deriving from Cnoc Fhinn, fair hill.