Definition of fold-up:
(v) :
(transitive) To bend (any thin material, such as paper) over so that it comes in contact with itself.
(v) :
(transitive) To make the proper arrangement (in a thin material) by bending.
(v) :
(transitive) To draw or coil (one’s arms, a snake’s body, etc.) around something so as to enclose or embrace it.
(v) :
(transitive, cooking) To stir (semisolid ingredients) gently, with an action as if folding over a solid.
(v) :
(intransitive) To become folded; to form folds.
(v) :
(intransitive, informal) To fall over; to collapse or give way; to be crushed.