See

1. Of parents and children; related by blood.
2. Pertaining to biology or to life and living things; SYN. biologic.

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. + prikaži više

ETYM Latin organicus, Greek: cf. French organique.
1. Of or relating to or derived from living organisms.
2. Being or relating to or derived from or having properties characteristic of living organisms.
3. (Chemistry) Relating or belonging to the class of chemical compounds having a carbon basis.
4. (Pathology) Involving or affecting physiology or bodily organs.
Structural; of or derived from living organisms; Medicine, of or affecting organ of body; Chemistry, of carbon compounds. + prikaži više

With respect to biology.