Princeton's WordNet

1. degree Fahrenheit, F(noun)

   a degree on the Fahrenheit scale of temperature

   Synonyms:
   fluorine, farad, degree Fahrenheit, atomic number 9

2. fluorine, F, atomic number 9(noun)

   a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite

   Synonyms:
   fluorine, farad, degree Fahrenheit, atomic number 9

3. farad, F(noun)

   the capacitance of a capacitor that has an equal and opposite charge of 1 coulomb on each plate and a voltage difference of 1 volt between the plates

   Synonyms:
   fluorine, farad, degree Fahrenheit, atomic number 9

4. F, f(noun)

   the 6th letter of the Roman alphabet

   Synonyms:
   fluorine, farad, degree Fahrenheit, atomic number 9