I had such great success with my last translation request, that I hope choosing a new language yields the same helpful response. Translating “pet of the devil dog” or “devil dog’s pet” from English to Irish Gaelic; would that accurately look like “peataí an madra diabhal”? Or would it be madra mallaithe? Or something I haven’t stumbled across yet?
Thanks in advance!
Irish living here but don’t speak the language. I think it’s Gaeilge (gwell-ga). Gaelic is the sport. Just wanted to clarify because I made that mistake at first and people here gt confused.
Gaeilge is Irish Gaelic for Irish Gaelic (If anyone is wondering, “Béarla” is Irish for “English”). The Irish might insist on calling it Gaeilge while in Ireland but it’s a bit like insisting English speakers refer to Spanish as Español when speaking English. But, when in Ireland do as the Irish.
Alas, my Irish skills are limited, but I think the phrase you have actually translates as “the pets are the devil’s dog” or something like that, because “pet” is in the plural form.
I’m taking a wild stab at it with the help of Google translate, and adding in a missing article and a preposition. I think “an peata ar diabhail madra” is closer to what you want but it still seems to lack something and is probably not exactly what you want.
Possessives are tricky in Irish. And descriptives often come after the noun they modify (like romance languages) but not always.
Hopefully someone more skilled in Irish will be along soon to help.
My books are packed at the moment, but I think you only need the second article—peata an mhadra diabhlaidhe?
I’m not sure what “devil dog” is in English, really. Diabhlaidhe is the adjective that goes with the noun “devil,” so “devilish”.
Can you please explain in English the meaning of the phrase you want to translate? Maybe with a little context. Then I can suggest an Irish translation.
Isn’t “Irish Gaelic” redundant? /not snark
Yes. No need for the “Gaelic” part. In English, the Irish Language is called, surprisingly, “Irish”. It gets a bit confusing because “Scots” refers to the Scottish dialect of English, not the Celtic language spoken in some places there.
No: there is also Scottish Gaelic and Manx Gaelic. Usually they’re referred to as Irish, Gaelic, and Manx, but when clarity is needed, "Irish Gaelic"distinguishes from the sister languages and from Hiberno-English.
Awaiting a rematch here. So, to the good Dr., “Gaelic” unadorned, in the right context, refers to the Scottish version.
Good topic for a drunken brawl in an Irish pub, I’d wager.
Thanks for the input so far! 
For those looking for more clarity on the ‘devil dog’ part; my better half is a Marine. For historical reasons (potentially apocryphal, but they don’t care), Marines are referred to/refer to themselves in certain circumstances as “Devil Dogs.” It is used in both the singular and plural form, depending on who is being addressed.
I’m making him a quilt for Christmas that is composed of old uniforms and unit tshirts, as well as some photo squares. One of the squares is of our cat, dressed in a tiny USMC uniform, who we sometimes refer to as “the Devil Dog’s pet.” While the origin of ‘Devil Dog’ is German (“Teufel Hunden” which yes, is grammatically incorrect), I am looking to honor the better half’s own genetic ancestry to tie into other portions of the quilt. Thus I need the translation into Irish Gaelic (and not, as Dr. Drake was kind enough to point out, Manx or Scottish Gaelic) so I can do a border around her square with the descriptor embroidered on it.
Does that help clear things up a little?
Yes, but for Scottish Gaelic, it’s pronounced gal-ick (gal rhymes with pal). Irish Gaelic is always gay-lick.
Are you talking about a pub where Irish is spoken or any pub in Ireland, regardless of the language spoken there? 
Yes. In that case, I’d reach further back in Irish. The word cú means “dog,” in Old Irish (now “hound”), but also “awesome warrior,” as in the name of the Irish hero Cú Chulainn.
Perhaps peata an chú shí. Cú sí is literally “fairy dog,” but they are supernatural creatures equivalent to English hellhounds and I think what your German phrase is going for. Sí is a lot tougher in Irish than the English translation would lead you to believe!
Guy goes into Chinese restaurant in NY. Waiters speak fluent Yiddish.
Guy to owner: Hey, I’m impressed.
Owner: Shh, they think they’re speaking English.
OK, the thought of using ‘fairy dog’ is cracking me up… I love it!!
ETA; What would be the difference between shí and sidhe?
Shí might be wrong; Hibernicus or someone can help.
Basically, there’s three things going on in Irish. One is spelling reform: idh and í sound the same, so old-fashioned sidh is modern sí.
Another is case: the possessive case can change the form, as in Latin or Old English.
Another is initial mutation: words that start with s change to sh (which just sounds like English h) in some environments. I can’t remember if this is one or not.
So there’s a bewildering variety of forms. Anything with the -dh- is using the old-fashioned spelling; the change in s / sh at the beginning has to do with grammar, as does the ending.
Fun!
The Irish call it “Irish” when speaking in English which outside of small communities is the common tongue.
You go to Irish class.
You can/can’t speak Irish.
Signs are in English and Irish.
As Dr Drake correctly explained, sí and sídhe are the same word, just different spelling conventions.
Thanks for the context, which clears things up a lot.
I want to suggest “peata chú an diabhail” (literally “the pet of the devil’s hound”); “peata an diabhalchú” (“the pet of the devil-hound”) or “peata an chú deamhanta” (“the pet of the demonic hound”).
I agree with you 100%, but there was a thread on here recently where this discussion came up and some Irish-based posters disagreed, stating that they refer to the language as Gaelic. I was surprised.
Disagreement begins at post #36.
Again, that is likely true in Ireland but on this side of the pond “Irish” can refer to either “Irish English” or “Irish Gaelic”, hence why I distinguish between them via what appears to you to be a redundancy.
Additionally, in regards to the OP - I think “Devil’s hound” conveys the meaning better than a more literal translation. So… “cú diabhail” for “devil dog” is my vote, for whatever that’s worth.