ETYM Old Eng. naturel, French naturel, from Latin naturalis, from natura. Related to Nature.
1. Existing in or in conformity with nature or the observable world.
2. Existing in or produced by nature.
3. In accordance with or determined by nature or natural laws.
4. Involving or derived from living organisms; free from chemical treatments or additives; SYN. nonsynthetic.
5. Relating to or concerning nature.
6. Related by blood; not adopted.
7. (Used especially of commodities) In the natural unprocessed condition; SYN. raw, rude.
8. (Music) Of a key containing no sharps or flats.
9. (Biology) Functioning or occurring in a natural way; lacking abnormalities or deficiencies.

In music, a sign canceling a sharp or flat. A natural trumpet or horn is an instrument without valves, thus restricted to playing natural harmonics.

1. Someone regarded as certain to succeed
2. A notation cancelling a previous sharp or flat; SYN. cancel.
3. (In craps) A first roll of 7 or 11 that immediately wins the stake.