Ó Dónaill's Foclóir Gaeilge-Béarla (1977) defines líofa as the following:

Ground, sharpened, polished by friction

Fluent, polished

Keen, eager

Sharp, speedy

Here it is used in several contexts:

Tá stíl an-líofa aici She has a very fluid style

roth líofa grinding wheel

Tá Spáinnis líofa aige He is fluent in Spanish

It has an alternative spelling of líomhtha and is related to líomhadh ("grind, sharpen, smooth"). Líomh comes from Old Irish límaid ("sharpens, grinds, polishes"). It could be borrowed from or related to Latin līmō ("I sharpen").  

The reason I dug into this was that the Scottish Gaelic word was entirely different: fileanta. Fileanta comes from filidh, file, filíocht ("poet, poetry"). Fileanta is defined as “eloquent, articulate, fluent”. 

Ó Dónaill’s Foclóir Gaeilge-Béarla (1977) defines clann as the following:

Children, offspring

Race, descendants

Followers

Plant (literary use)

Lock (of hair)

Weaving: Two interlocked threads on warping frame

Clann comes from the Old Irish cland (children), through Old Welsh plant (children), from Latin planta (shoot, twig, sprout).

Further Reading:

Spelling: Why the ‘P’ evolved to a ‘C’ (compare plant/cland)

Online Etymology Dictionary further expands from Latin planta:

We previously discussed the religious origins of nóin and tráthnóna.

By the 9th century, basic cycles of prayer provided the structure for daily life in monasteries, called canonical hours. Here are three borrowed into common use:

Office of Readings (Matins)

Midafternoon prayer (None)

Evening prayer (Vespers)

Maidin

The word maidin, for morning, comes from the Latin mātūtīnus (Matins, or the Office of Readings), meaning “of the morning”, and was brought to Irish via the Catholic church.

Nóin and tráthnóna

As previously discussed, Nóin comes from the midafternoon prayer, or None. Tráthnóna refers to the Hour of Nones.

Feascar

Although rare, the term feascar is also used in certain circumstances to mean “evening”:

i bhfeascar a lae; i bhfeascar a aoise in the evening of his life

This comes from the evening prayer, or Vespers. Vespers, specifically referring to the prayer, became easparta in Irish. We see feasgar more in Scottish Gaelic, where feasgar math would be the equivalent of the greeting tráthnóna math.

Further Reading:

Spelling: Why the ‘P’ evolved to a ‘C’ (compare vesper/feascar)

It’s hard to exclude Scottish Gaelic when learning Irish, as there is a whole lot of overlap. Comparing what each calls the months of the year is a fun one as it highlights certain historical and cultural differences.

Gaeilge Eanáir Feabhra Márta Aibreán Bealtaine Meitheamh Iuil Lúnasa Meán Fómhair Deireadh Fómhair Samhain Nollaig

Etymology Latin Iānuārius Latin Februārius Latin Martius Latin Aprīlis Old Irish Beltane Old Irish Mithem Latin Iūlius Old Irish Lugnasad Mid-harvest End-of-harvest Old Irish Samhain Latin nātālīcia

Gàidhlig Am Faoilleach An Gearran Am Màrt An Giblean An Cèitean An t-Ògmhios An t-Iuchar An Lùnastal An t-Sultain An Dàmhair An t-Samhain An Dùbhlachd

Etymology Wolf Month The Cutting Latin Martius Pudding Month from Cètshamain Month of the Young Warm month Old Irish Lugnasad Month of fatness The Rutting Old Irish Samhain The Darkness

Historically, these terms have never strictly adhered to the modern day Gregorian calendar. Terms like Déireadh Fómhair—marked by the end of the harvest—could be from as early as September to mid-November depending on the weather.

The Irish Bealtaine and Gaelic An Cèitean are synonyms. The Scottish Gaelic Céitean refers to céad shamhain, which I covered in a previous post. Additionally, it is stated in Ó Duinnín's Foclóir Gaedhilge agus Béarla (1927) that Mí Céadamhan is the month of May, which means that both forms were used in Irish.

Some Ulster writers also use Mí na bhFaoillí or Mí na bhFaoilleach for January.

Another one that they actually do have in common as well is Deireadh Fómhair, as Scottish Gaelic also uses mìos deireannach an fhoghair. However, Gaelic tends to use the term for September, sometimes October and up to mid-November. Mìos Deireannach an t-Samhraidh is the archaic Scottish Gaelic term for July.

Inis and oileán both refer to an island. Inis is mostly only seen in placenames as it is archaic and comes from the Latin insula. Peninsula stems from the same word. 

Oileán, on the other hand, comes from the Old Irish ailén or ail, and is used in modern Irish to refer to an island. Logainm gives oileán as “island”, and inis as “island; river meadow”. 

Comparing the Irish oifig to Scottish Gaelic oifis, I wondered about the unusual difference in the two. Usually, spelling differences between these two languages tend to involve these common corresponding consonants: c/t in Irish vs g/d in Scottish Gaelic and some diphthongs like eo/ea in Irish and eu in Scottish Gaelic, just to name a few.