Webster’s Revised Unabridged Dictionary · 1913
Faucal
Fau′cal, 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.
Ayin is the most difficult of the faucals. I. Taylor (The Alphabet).