In The Raven, what is most closely the meaning of the word countenance as it is used in the following passage?

Then this ebony bird beguiling my sad fancy into smiling,
By the grave and stern decorum of the countenance it wore,
“Though thy crest be shorn and shaven, thou,” I said, “art sure no craven,
Ghastly grim and ancient Raven wandering from the Nightly shore —
Tell me what thy lordly name is on the Night’s Plutonian shore!”
Quoth the Raven “Nevermore.”