Sun in WordNet English dictionary

1. first day of the week; observed as a day of rest and worship by most Christians
   Sunday  Lord's Day  Dominicus  Sun 
   
2. the star that is the source of light and heat for the planets in the solar system
   "the sun contains 99.85% of the mass in the solar system"; "the Earth revolves around the Sun"
   sun  Sun 
   
3. the star that is the source of light and heat for the planets in the solar system
   "the sun contains 99.85% of the mass in the solar system"; "the Earth revolves around the Sun"
   sun  Sun