muse

Noun

• the source of an artist's inspiration
  • Euterpe was his muse
    

• in ancient Greek mythology any of 9 daughters of Zeus and Mnemosyne; protector of an art or science

Verb

• reflect deeply on a subject
  • I mulled over the events of the afternoon
    
  • philosophers have speculated on the question of God for thousands of years
    
  • The scientist must stop to observe and start to excogitate