stone

Concise Oxford English Dictionary © 2008 Oxford University Press:
stone/stəʊn/

▶noun

• 1 hard, solid non-metallic mineral matter of which rock is made.

  ■ a small piece of stone found on the ground.

  ■ a piece of stone shaped for a purpose, especially one of commemoration or demarcation.

  ■ Astronomy a meteorite made of rock, as opposed to metal.

  ■ Medicine a gallstone or kidney stone; a calculus.

• 2 a gem.

• 3 a hard seed in a cherry, plum, peach, etc.

• 4 (pl. same) Brit. a unit of weight equal to 14 lb (6.35 kg).

• 5 a whitish or brownish-grey colour.

▶verb

• 1 throw stones at in order to injure or kill.

• 2 remove the stone from (a fruit).

• 3 build, face, or pave with stone.

▶adverb extremely or totally: stone cold.

– phrases
be written (or carved or set) in stone be fixed and unchangeable.
leave no stone unturned try every possible course of action in order to achieve something.
a stone's throw a short distance.

– derivatives
stoneless adjective.

– origin OE stān (n.), of Gmc origin.