S: (n) speed of light, light speed, c (the speed at which light travels in a vacuum; the constancy and universality of the speed of light is recognized by defining it to be exactly 299,792,458 meters per second)
S: (n) vitamin C, C, ascorbic acid (a vitamin found in fresh fruits (especially citrus fruits) and vegetables; prevents scurvy)
S: (n) deoxycytidine monophosphate, C (one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose))
S: (n) cytosine, C (a base found in DNA and RNA and derived from pyrimidine; pairs with guanine)
S: (n) carbon, C, atomic number 6 (an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds)