What is "to eat in"

Eat \Eat\, v. i.

1. To take food; to feed; especially, to take solid, in distinction from liquid, food; to board.

   He did eat continually at the king's table.
   --2 Sam. ix. 13.

2. To taste or relish; as, it eats like tender beef.

3. To make one's way slowly.

   To eat, To eat in or To eat into, to make way by corrosion; to gnaw; to consume. ``A sword laid by, which eats into itself.''
   --Byron.

   To eat to windward (Naut.), to keep the course when closehauled with but little steering; -- said of a vessel.