Hi, I'm an aspiring writer working on his first story, and I was wondering if I could get some help with this.

Long story short, I'm writing an urban fantasy story set in an alternate version of 1990s America where every species of mythical humanoid that humanity has ever believed to be real turns out to exist, or at least used to before going extinct. They are collectively called immortals, due to them all having eternal youth. In this setting, leprechauns have a significant role as the financial powerhouses of the secret magical world. Five powerful leprechaun families jointly run a company called PRISM, which, among other things, owns the bank that nearly all American immortals use. They make it easier for immortals to maintain their assets between multiple false identities over the years, help coordinate the sale of goods and services that the mundane world isn't supposed to know exist, and are an aggressively neutral power amidst a bunch of clans squabbling for territory. They don't try to influence the surrounding political landscape (much), but they do not take kindly to being stolen from, and they have a payroll of immortal hired guns ready to reclaim what is rightfully theirs the second the need should arise.

I was wondering a bit about what this group of hired guns should be called, and then a random thought occurred to me:

"Why don't you Google what "loss prevention" is in Irish? Wouldn't it be hilarious if that turned out to sound cool?"

And initial research suggested that, to my utter disbelief... it actually might.

Google told me that the Irish translation of "Loss Prevention" is "Cosc Caillteanas", which if I understand correctly is pronounced like "Cosk Caltinus". Now, if that's true, that actually sounds pretty cool to my American ears. It's alliterative, and it has a really nice rhythm to it. As somebody who does not understand a word of Irish, it sounds really cool and ominous, an excellent name for an organization of elite mercenaries tasked with enforcing the will of the rich and powerful. ...But I also know the minefield of perils that come from relying on Google translate, and I know full well how likely it is that if I stopped here without checking, I'd probably have something similar to when the creator of the anime Sword Art Online took his skull-masked, gunslinging villain and gave him the comically edgy English name "death gun".

So I wanted to check with someone who knows better than I do. I could be mispronouncing it, or I could be using the wrong definitions of "loss" and "prevention" simultaneously, or I could be doing any number of things that would make using this term utterly ignorant and laughable, so I'd better ask about it here before I get too excited.

Thank you for your time!

either
cosc ar chaillteanas
or
cosc caillteanais

And the latter would be plural? The equivalent to "Losses Prevention"?

No, it is genitive singular.
Both mean the same: loss prevention