There are multiple definitions:

1. chemical oxygen demand(English)

   • indicative measure of the amount of oxygen that can be consumed by reactions in a solution
   • EPA
   • Environment, Oxygen
   • https://camblab…/index.php/272/

2. cause of death(English)

   • MOD
   • Pathology, Diagnostics

3. coefficient of dispersion(English)

   • Statistics

4. critical organ dose(English)

   • energy deposited per unit mass to an individual critical organ
   • DAP, FAD, SAD
   • Radiotherapy /radiation
   • https://pubs.rs…48/rg.285075748

5. cemento-osseous dysplasia(English)

   • FCOD, OD
   • Dentistry
   • https://doi.org…2903-017-0455-5

6. co-occurring [mental] disorder(English)

   • FMHS, SUD
   • Mental health, Addiction and health, Forensic medicine, Psychiatry
   • https://doi.org…sat.2022.108899