What is the meaning of "غط غطيطًا وأزبد شدقاه"?

Al-Ghateet is snoring, the gurgling of water, and the roaring of a camel. So it is said, "the sleeper 'ghatta'" if he snored and made a sound in his sleep, and "the camel 'aghatta'" if it roared, and likewise for water. As for "froth from its jaws," its meaning is: froth came out from them, which is the foam when a camel roars or water gurgles.