1. A fairly common given name in Greece.
2. In the fictional Marvel Comics Universe, "Lord" Thanos (derived from Thanatos, God of Death) is a tall buff purple alien supervillain with a washboard chin and dark, gleaming eyes. He was born on Saturn's moon Titan to the race called the Eternals, but later nuked his homeworld from orbit. He worships his deity/lover, Mistress Death, and often tries to gain power so as to destroy entire galaxies or universes in Death's service. Eventually he died and joined Mistress Death as her consort.
3. Rev. Dr. Thanos Q. "Elohim" Endrizzi, Ph.D., the avatar / online persona of the Founder and Lord High Reverend of the secretive Church of Metaversalism
, which claims that all possible Gods and universes exist. Dr. Thanos is famed for promoting Metaversalist ideas on various social networks as well as in Second Life. His appearance resembles Marvel's Thanos, except he has bushy white hair and glasses. His character bio says he's based on Marvel's character, but reformed since his old days, and is trying to save the universe, not destroy it. Many agree that Dr. Thanos has a keen mind, and is a clear , logical thinker with a solid understanding of a wide range of math and science concepts. He's often complimented on his clear explanations, but has also been accused of being long-winded, arrogant, and overly confident in his philosophy.
3. Anyone who has similar characteristics to either of the above two versions of Thanos.