car·bon·yl 
(kärbə-nĭl′)
(kärbə-nĭl′)n.
1. The bivalent group C＝O.
2. A metal compound, such as Ni(CO)4, containing the CO group.
car′bon·ylic adj.
- apoplexy
- apoptosis
- aporia
- aport
- aposematic coloration
- aposiopesis
- aposiopetic
- aposporic
- aposporous
- apospory
- apostasy
- apostate
- apostatize
- a posteriori
- apostle
- apostlehood
- "Apostle of the English."
- Apostles' Creed
- apostleship
- apostolate
- apostolic
- apostolical
- apostolically
- apostolic delegate
- Apostolic Father