phosphorus

Noun

• a planet (usually Venus) seen just before sunrise in the eastern sky

• a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms

Related words

• Synonyms: 
  morning star , daystar , Phosphorus , Lucifer , P , atomic number 15