Definition of scrunches:
(v) :
(transitive) To crumple and squeeze to make more compact.
(v) :
(with object "one's face") To contract the muscles of one's face so as to draw their facial features together, out of pain, discomfort, uncertainty, etc.
(n) :
A crunching noise.
(v) :
Alternative form of scranch. [(transitive, archaic) To grind with the teeth, and with a crackling sound; to crunch.]