Foam - Vine's Expository Dictionary of New Testament Words
Foam[ A-1,Verb,G875, aphrizo ]
denotes to foam at the mouth" (akin to aphros, "foam;" See B.), Mark 9:18, Mark 9:20.
[ A-2,Verb,G1890, epaphrizo ]
"to foam out, or up" (epi, "up," and No. 1), is used metaphorically in Jude 1:13, of the impious libertines, who had crept in among the saints, and "foamed" out their own shame with swelling words. The metaphor is drawn from the refuse borne on the crest of waves and cast up on the beach.
[ B-1,Noun,G876, aphros ]
"foam," occurs in Luke 9:39, where it is used with the preposition meta, "with," lit., "(teareth him) with (accompanied by) foam."