Definition of "viscid"

They trod noiselessly upon a stair carpet that its own loom would have forsworn. It seemed to have become vegetable; to have degenerated in that rank, sunless air to lush lichen or spreading moss that grew in patches to the staircase and was viscid under the foot like organic matter.

1906, O. Henry, The Furnished Room

The pool’s bottoms and sides were lined with a blanket of viscid slime, and the three statues in the middle, the three Sirens of Titan, were under a mucilaginous hump.

1959, Kurt Vonnegut, The Sirens of Titan‎, New York: Dial, published 2006, Epilogue, pp. 315-316