Merriam-Webster Collegiate Dictionary - burrow

 I. noun  Etymology: Middle English borow  Date: 13th century a hole or excavation in the ground made by an animal (as a rabbit) for shelter and habitation  II. verb  Date: 1602  transitive verb  1. archaic to hide in or as if in a ~  2.  a. to construct by tunneling  b. to penetrate by means of a ~  3. to make a motion suggestive of ~ing with ; nestle ~s her hand into mine  intransitive verb  1. to conceal oneself in or as if in a ~  2.  a. to make a ~  b. to progress by or as if by digging  3. to make a motion suggestive of ~ing ; snuggle, nestle ~ed against his back for warmth  • ~er noun