What is the meaning of the word "clog"?

Definitions:

to become or cause to become obstructed verb
- The leaves clog our drains in the fall.
to dance a clog dance verb
- I clog at festivals to the great amusement of my friends.
to fill to excess so that function is impaired verb
- Fear clogged my mind before I started meditation.
to impede the motion of, as with a chain or a burden verb
- horses were clogged until they were tamed
to impede with a clog or as if with a clog verb
- The market is being clogged by these operations