From Longman Dictionary of Contemporary Englishmunchmunch /mʌntʃ/ verb [intransitive, transitive] DFEATto eat something noisilymunch on/at Barry sat munching on an apple. They’d munched their way through (=eaten all of) three packets of biscuits.→ See Verb table
Examples from the Corpus
munch• Jamie came out of the store munching a bag of potato chips.• His son, Francis, was munching away, his protuberant eyes fixed on his father in an unwavering stare.• Mice munch away on aconites and love to nibble newly sown peas and beans.• He took it out to hold and to watch it munch clover.• We then watched it buttonhole every munching matriarch in the flock, crying, ` Did you see?• Who wants to count calories and munch on a piece of dry toast at such a time?• We sipped black coffee and munched on homemade biscuits.• Hodges finally sits, and I munch on sour dough bread in between sips of the luscious vintage.• kids munching popcorn at the movies• I munched secretively, washing my food down with a swallow, of coffee.• Their conversation had a munching sound.munch on/at• Who wants to count calories and munch on a piece of dry toast at such a time?• We sat with the four or five others already there and began munching on bread baked in the adjacent kitchen.• A roe deer came down into reeds opposite to munch at green stuff.• The dolls are supposed to munch on plastic food that comes in the box.• Hodges finally sits, and I munch on sour dough bread in between sips of the luscious vintage.Origin munch (1300-1400) Probably from the sound of food being crushed