faecal

a. [ L. fauces throat. ] Pertaining to the fauces, or opening of the throat; faucial; esp., (Phon.) produced in the fauces, as certain deep guttural sounds found in the Semitic and some other languages. [ 1913 Webster ]

Ayin is the most difficult of the faucals. I. Taylor (The Alphabet). [ 1913 Webster ]