My Collins dictionary says faugh! is an exclamation of disgust, scorn, etc, but without mentioning that the last person to use it probably died in the first half of the last century.
Now, one of the reasons for faugh's sad demise must be that hardly anyone knows how to pronounce it (I didn't) but Collins tells me that faugh rhymes with phwoar, law, and cor (English spelling eh?).
Anyway, disgust or scorn...I think I'm going to enjoy using this one.
Word To Use Today: faugh!
I ought to mention that according to Merriam-Webster faugh sort-of rhymes with back, though with the final sound throatier, as at the end of loch.