"We eat a completely other thing."
Translation:Ithimid rud eile ar fad.
I’d prefer “We eat another thing entirely” as a translation of this sentence. Given that, here’s my attempt at context:
Visitor from the Andromeda galaxy: “For dessert, we’re quite fond of mercury-coated lithium. How about you?”
Earthling: “We eat another thing entirely. Mercury and lithium are both poisonous to us.”