Scrunch belongs to early 19th century, of imitative origin, a variant of 'crunch' (or 'scrounge'), expressing a crushing or grinding sound. The historical chain includes onomatopoeic scrunch. The quoted older senses, "crunch" and "scrounge", supply the semantic anchors for scrunch. In present English it is used as a verb, "to crush or crumple, or to make a crunching sound". English derivatives include scruncher and scrunchy; related English forms include crunch and scrunchie. The result is a verb and noun whose etymology preserves both the older form and the later English specialization.