Definitions of Sidney:

• noun:   English poet (1554-1586)
• name:  A male given name (common: 1 in 1923 males; popularity rank in the U.S.: #274)
• name:  A female given name (rare: 1 in 25000 females; popularity rank in the U.S.: #1483)
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #10979)