Synonyms for Pig out:

n.

pig out (noun)
scarf out, englut, glut, binge, ingurgitate, satiate, overgorge, engorge, gourmandize, gorge, stuff, overindulge, gormandise, gormandize, overeat.

v.

eat a lot (verb)
gormandize, overeat, overindulge, binge, gorge, scarf out.

Other synonyms:

englut
englut.
overeat
gourmandize.