burrow (burrows plural & 3rd person present) (burrowing present participle) (burrowed past tense & past participle )
1 n-count A burrow is a tunnel or hole in the ground that is dug by an animal such as a rabbit.
2 verb If an animal burrows into the ground or into a surface, it moves through it by making a tunnel or hole.
(=tunnel)
The larvae burrow into cracks in the floor. V prep/adv
3 verb If you burrow in a container or pile of things, you search there for something using your hands.
He burrowed into the pile of charts feverishly. V prep/adv
4 verb If you burrow into something, you move underneath it or press against it, usually in order to feel warmer or safer.
She turned her face away from him, burrowing into her heap of covers. V prep/adv