S in WordNet English dictionary

1. an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
   sulfur  S  sulphur  atomic number 16 
   
2. the cardinal compass point that is at 180 degrees
   south  due south  southward  S 
   
3. (thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
   "entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity"
   randomness  entropy  S 
   
4. a unit of conductance equal to the reciprocal of an ohm
   mho  siemens  reciprocal ohm  S 
   
5. the 19th letter of the Roman alphabet
   S  s 
   
6. the 19th letter of the Roman alphabet
   S  s