" (mountain-)stream of Eilís? Eilís

I bhfad siar ar Fóram Daltaí rinne mé tagairt do thagairt atá ag Biddy Jenkinson i scéal Bleachtaireachta dá cuid faoin tAthair Dinneen do Ghaeilge a bheith tree tattoo fós á labhairt tree tattoo i nGleann an Smóil lena linn. Fiafraíodh díom faoi ar Twitter ar na mallaibh, ach ní raibh d'fhianaise agam ach an tagairt sin.
" (mountain-)stream of Eilís? Eilís — ainm pearsanta mná? Triomán / tromán — a term for a (mountain-)stream that occurs tree tattoo in the hills of County Wicklow and south County Dublin. Tromán is the spelling Eoghan Ó Comhraí used in the Ordnance Survey Letters for the word as he heard it from the Irish speakers of Glenasmole (e.g. ‘Bun na ttrí ttromán’), which would imply that the word is based on a secondary sense of the adjective tree tattoo trom (primarily ‘heavy’, etc.) with the diminutive suffix -án . But see also A Dictionary of the Irish Language s.v. tírmán , ‘exsiccator’: perhaps these names reflect triomán , in the sense ‘stream which drains water from the hills’. See also the name An Triomóg / Trimoge River in County Mayo. It is difficult to ascertain the origin of the qualifying element here, however, for lack of evidence: -(n)ellish , -(n)ellis , and (-n)Allison are the only surviving forms. It appears that the forms in -ellis(h) represent the female personal name Eilís (< Elisabetha ), and the form given to Ó Comhraí is rather an explanation tree tattoo of the name (cf., perhaps, both Aill Mháire and Aill Mháirín given for Mareen’s Brook ); there is also a surname tree tattoo Eilís (< Ellis , Ellison ). Or it may be a corrupted form of the plant-name feileastram , ‘iris’ (this plant has been recorded along the Dodder at Ballinascorney and Castlekelly) or some other dissimilation of the consonants /l/, /n/, /r/. In the hills of southwest County Dublin another term for (mountain-)stream occurs, namely slád (which originally had the sense ‘glen’, ‘vale’; it comes from the English slade ), e.g. Slád na Cloiche Báine , ‘the stream of the white stone’; Slád na Riaibhche , ‘the stream of the brindled cow’, in the civil parish of Saggart. In the Glens of Antrim Holmer found allt , which usually means ‘glen’, ‘vale’, in that area, used specifically as a term for the streams flowing through those small glens (cf. Aill Mháirín here in Glenasmole). Note that stream-names based on the word sruth ( án ) also occur alongside both of these terms: in 1937 Liam Price noted the name ‘Srugh’ for what is marked on the maps as Slade Brook in Glenasmole, 600m from Tromanallison , for example." Sé mo thaithí go mbíonn flosc agus eolas ag taighdeoirí An Bhrainse Logainmneacha, agus sheol mé ceist tríd an suíomh. Fuair mé an t-eolas chuimsitheach anseo thíos ó Aindí Mac Giolla Chomhghaill ón mBrainse:
Is iad Litreacha na Suirbhéireachta Ordanáis an príomhfhoinse atá againn ar Ghaeilgeoirí Ghleann an Smóil sa 19ú haois. Bhí an taighde ar logainmneacha Chontae Bhaile Átha Cliath nach mór curtha i gcrích ag an tSuirbhéireacht nuair a thug an scoláire Eoghan Ó Comhraí cuairt ar an ngleann i samhradh tree tattoo na bliana 1837 chun fuaimniú áitiúil na logainmneacha a fháil ó mhuintir na háite (chomh maith lena raibh ann de shéadchomharthaí a iniúchadh). Tugaim anseo i mo dhiaidh tras-scríobh de na litreacha a bhaineann leis an ngleann, tree tattoo as na bunchóipeanna atá le fáil in Acadamh Ríoga na hÉireann (cuirim cló iodálach ar aon rud a scríobhtar i bpeannaireacht na Gaeilge):—
I went on yesterday [.i. Dé Máirt, 25/7/1837] to Tallagh and visited a mountain above Ballynascorney tree tattoo called by the people Suíghchán , i.e. the seat. It is a very high boggy mountain … I descended the east side of the mountain into Glen a Smoil, the far famed residence of the mighty Finn Mac Cool. There are many old recollections of him still in this glen. However I had not time enough left to make more than a passing enquiry, but expect to collect some curious facts when I visit it again, which I hope to be able to do on Friday next [.i. 28/7/1837] .
  Since I wrote to you last I visited Glen-a-smoil and the neighbouring mountains twice. I could collect no tradition of Finn Mac Cool or his warriors in the glen, but what is current all over Ireland. The most remarkable features of this celebrated Glen are the four mountain streams that descend into it and form the River Dodder. 
  The first and largest of these streams, which is called Aill Mháire , or Mareens brook, rises in Kippure tree tattoo mountain near Lough Bray and rolls down a rocky precipitate channel to Castle Kelly in the Glen, a little below which it meets the Dodder or Aidhin Dothar .
  a small stream which takes its rise in a Slough called tromán Dubh (black stream) some distance to the north [ recte south] of Mareens Brook on Kippure ridge, and running down through Coill mhór and receives the stream of Lug Mor, immediately before it j