six feet under

beat feet

To run.

deep six

To discard, get rid of, or cancel; to completely put an end to something.

drag one's feet

To procrastinate, put off; to dawdle, avoid, or make progress slowly and reluctantly.

feet first

In the manner of a deceased person (i.e., dead).

feet of clay

In someone apparently strong and without failings, a hidden weakness which could lead to downfall.

find one's feet

To grow in confidence in a new situation as one gains experience.

get one's feet wet

To begin gaining experience; to tentatively try something new.

get to one's feet

To stand up.