ConceptNet
An encyclopedia of concept simulations that computers and humans can learn from.
An experimental project in machine learning.

cliff
the high, steep side of a mountain or rock.

crush
to damage something by squeezing it very hard.

crumble
break or fall apart into small fragments, especially over a period of time as part of a process of deterioration

flap
to move up and down.

drip
to fall slowly, drop by drop.

meet
to come face-to-face with another person

stack
a pile of things, one on top of another.

sort
to arrange things into different types or groups.

cover
to put something over or on something else.