1. quaternary ammonium compound a compound derived from ammonium with hydrogen atoms replaced by organic groups; used as surface-active agents, disinfectants, and in drugs
  2. coordination compound a compound described in terms of the central atom to which other atoms are bound or coordinated
  3. inorganic compound any compound that does not contain carbon
  4. heterocyclic compound a compound containing a heterocyclic ring
  5. organic compound any compound of carbon and another element or a radical
  6. Quaternary period last 2 million years
  7. anionic compound a compound characterized by an active anion
  8. aromatic compound a hydrocarbon containing one or more benzene rings that are characteristic of the benzene series of compounds
  9. binary compound chemical compound composed of only two elements
  10. genus Camponotus carpenter ants
  11. anti-TNF compound a class of drugs that block the action of tumor necrosis factor (TNF); used in cases of rheumatoid arthritis because TNF instigates inflammation of the joints
  12. chemical compound (chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
  13. incumbent necessary as a duty or responsibility; morally binding
  14. ammonium carbonate a carbonate of ammonium
  15. western chimpanzee masked or pale-faced chimpanzees of western Africa
  16. Western Roman Empire the western part after the Roman Empire was divided in 395
  17. Eastern Roman Empire a continuation of the Roman Empire in the Middle East after its division in 395
  18. compound a whole formed by a union of two or more elements or parts
  19. German monetary unit monetary unit in Germany
  20. mainframe computer a large digital computer serving 100-400 users and occupying a special air-conditioned room