WordNet (r) 3.0 (2006):

grub up
    v 1: dig up; "grub up roots and tree stumps" [syn: grub up,
         grub out]

Moby Thesaurus II by Grady Ward, 1.0:

69 Moby Thesaurus words for "grub up":
   accumulate, amass, assemble, avulse, bring together, collect, cull,
   cut out, deracinate, dig out, dig up, disentangle, draw, draw out,
   dredge, dredge up, eradicate, evolve, evulse, excavate, excise,
   exsect, extract, extricate, ferret out, fish out, gather,
   gather in, get in, get out, get together, glean, gouge out, grub,
   hunt out, mine, pick, pick out, pick up, pluck, pluck out,
   pluck up, pry out, pull, pull out, pull up, quarry, rake out,
   rake up, remove, rip out, root out, root up, round up, scare up,
   scout out, scrape together, scrape up, search out, spy out,
   take out, take up, tear out, unearth, unravel, uproot, weed out,
   withdraw, wrest out