Guest Q, you say we have "dropped the feminine simpatica", but I would guess we never really had it. I think "simpatica" in English is a humorous variant, akin to "macha" or "loca". I presume you're thinking of it because of its occurrence in the 1864 OED citation, but note the noun it describes! I don't think the same writer would have said "Mrs. Jones was less 'simpatica.'" Because Mrs. Jones is a straight-faced person to talk about, while "The Frau-Professorin" is, before her title is out of your mouth, a catalyst of wit. English is quite stingy with its tolerance for gender in adjectives.

As for the á, that's only in the Spanish etymon; in its Italian cognate, which is probably whence it entered English (notwithstanding its recent popularity in the US SW), it is naked of diacriticism.

As for a Gaelic word being "necessary", of course not, but if we only used the words that were necessary this would be a pretty skimpy Café dontcha think?!

Alice, you write "I just looked in my Irish-English dictionary, and simpatico is not there"; this comes as no surprise, but also as no proof. If you try using it in conversation with Irish-speakers, imbedded in Irish sentences, and are generally understood and no one objects, then lo and behold if it wasn't previously it is now an Irish word, and the fault is the dictionary's.

"The word most like simpatico I found was under sympathetic (likeable) 'báúil'." I don't know a whole lot of Irish ;-|, but my guess is that Declan's 'Dlúth-chara' is closer, in terms of emotive semantics. But of course it's an adjective, not a noun.

Haruo