grubnoun1.•a small black grub:larva | maggot | caterpillar.2.informal •we'll grab some grub on the way. See food (sense 1).▶verb1.•they grubbed up the weeds:dig up, unearth, uproot, root up/out, pull up/out, tear out.2.•he began grubbing around in the trash:rummage, search, hunt, delve, dig, scrabble, ferret, root, rifle, fish, poke.