galileo
n. countablen. a famous Italian scientist from the 1600s who studied the stars and planets. He is best known for using a telescope to prove that the Earth moves around the Sun.
n. a 17th-century Italian astronomer, physicist, and polymath who played a central role in the Scientific Revolution. His support for heliocentrism led to a famous conflict with the Catholic Church.
Galileo used his telescope to look at the moons of Jupiter.
Many historians consider Galileo the father of modern observational astronomy because of his improvements to the telescope.
The conflict between Galileo and the Roman Inquisition remains a defining historical example of the tension between empirical scientific observation and established religious authority.
Used as a proper noun to refer to the historical figure; occasionally used as a countable noun to refer to spacecraft or projects named after him.