Webster's Revised Unabridged Dictionary · 1913

Pore

Pore , noun

[French, from Latin porus, Greek {not transcribed} a passage, a pore. See Fare, v.]

1.
One of the minute orifices in an animal or vegetable membrane, for transpiration, absorption, etc.
2.
A minute opening or passageway; an interstice between the constituent particles or molecules of a body; as, the pores of stones.

Pore , intransitive verb

[Old English poren, of uncertain origin; compare Dutch porren to poke, thrust, Gael. purr.]

To look or gaze steadily in reading or studying; to fix the attention; to be absorbed; -- often with on or upon, and now usually with over.
Painfully to pore upon a book. — Shakespeare
The eye grows weary with poring perpetually on the same thing. — Dryden