[1] : WordNet (r) 2.0

stack up
     v : arrange into piles or stacks; "she piled up her books in my
         living room" syn: pile up, heap up
see also:
pile up heap up 

[2] : Moby Thesaurus II by Grady Ward, 1.0

101 moby thesaurus words for "stack up":
   admit of comparison, amount to, ape, appear like, approach,
   approximate, arrival, balance, bank, bank up, be commensurable,
   be comparable, be like, be redolent of, be so, be such,
   bear resemblance, blind landing, break even, bring to mind,
   call to mind, call up, come along, come close, come near, come on,
   come out, come through, come to, come up to, coming in, compare,
   compare to, compare with, contrive, copy, correspond, counterfeit,
   ditto, draw, drift, equal, even, even off, evoke, fare, favor,
   follow, get along, get by, get on, go along, go on, heap, heap up,
   hill, imitate, keep pace with, knot, landing, look like, make out,
   manage, match, match up with, measure up to, mimic, mirror, mound,
   near, nearly reproduce, not compare with, not tell apart, parallel,
   partake of, pile, pile up, pyramid, reach, remind one of, resemble,
   rick, rival, run abreast, run to, savor of, seem like, shape up,
   simulate, smack of, sound like, stack, stack up with, suggest,
   take after, tie, touch, touchdown, turn out, vie, vie with

Ball Up >> B Words
Ball Up, definition of term: Ball Up
ball+up_pag1.html

Bang Up >> B Words
Bang Up, definition of term: Bang Up
bang+up_pag1.html

Backed Up >> B Words
Backed Up, definition of term: Backed Up
backed+up_pag1.html

Back Up >> B Words
Back Up, definition of term: Back Up
back+up_pag1.html

Ante Up >> A Words
Ante Up, definition of term: Ante Up
ante+up_pag1.html

Act Up >> A Words
Act Up, definition of term: Act Up
act+up_pag1.html