Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun co2

1 sense of co2

Sense 1
carbon dioxide, CO2, carbonic acid gas -- (a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis)
       => dioxide -- (an oxide containing two atoms of oxygen in the molecule)
       => greenhouse gas, greenhouse emission -- (a gas that contributes to the greenhouse effect by absorbing infrared radiation)