Search Result for "carbon cycle":
Wordnet 3.0

NOUN (2)

1. the organic circulation of carbon from the atmosphere into organisms and back again;

2. a thermonuclear reaction in the interior of stars; 



WordNet (r) 3.0 (2006):

carbon cycle
    n 1: the organic circulation of carbon from the atmosphere into
         organisms and back again
    2: a thermonuclear reaction in the interior of stars