empty

Concise Oxford English Dictionary © 2008 Oxford University Press:
empty/ˈempti/

▶adjective (emptier, emptiest)

• 1 containing nothing; not filled or occupied.

  ■ Mathematics (of a set) containing no members or elements.

• 2 (of words or a gesture) lacking sincerity.

• 3 having no value or purpose.

▶verb (empties, emptying, emptied)

• 1 make or become empty.

  ■ discharge (the contents) from a container.

• 2 (of a river) discharge itself into the sea or a lake.

▶noun (pl. empties) informal a bottle or glass left empty of its contents.

– phrases
be running on empty have exhausted all of one's resources.

– derivatives
emptily adverb,
emptiness noun.

– origin OE ǣmtig, ǣmetig ‘at leisure, empty’, from ǣmetta ‘leisure’.