Webster's Revised Unabridged Dictionary · 1913

Grub

Grub (grub) , intransitive verb

[Old English grubbin., compare English grab, grope.]

1.
To dig in or under the ground, generally for an object that is difficult to reach or extricate; to be occupied in digging.
2.
To drudge; to do menial work. — Richardson

Grub , transitive verb

1.
To dig; to dig up by the roots; to root out by digging; -- followed by up; as, to grub up trees, rushes, or sedge.
They do not attempt to grub up the root of sin. — Hare
2.
To supply with food. [Slang] — Dickens

Grub , noun

1.
(Zoology) The larva of an insect, especially of a beetle; -- called also grubworm. See Illust. of Goldsmith beetle, under Goldsmith.
Yet your butterfly was a grub. — Shakespeare
2.
A short, thick man; a dwarf. [Obsolete] — Carew
3.
Victuals; food. [Slang] — Halliwell
I 'd sooner ballads write, and grubstreet lays. — Gap