Quick Quiz: Nouns Score: Change category, Flip order Reset Correct! Noun: ctenophore Your choice? a metric unit of capacity equal to the volume of 1 kilogram of pure water at 4 degrees centigrade and 760 mm of mercury (or approximately 1.76 pints) any of numerous European and North American birds having pointed wings and a long tail biradially symmetrical hermaphroditic solitary marine animals resembling jellyfishes having for locomotion eight rows of cilia arranged like teeth in a comb the volume equal to a cube one inch on each side