Definitions of plough:

• noun:   a farm tool having one or more heavy blades to break the soil and cut a furrow prior to sowing
• noun:   a group of seven bright stars in the constellation Ursa Major
• verb:   move in a way resembling that of a plow cutting into or going through the soil
• verb:   to break and turn over earth especially with a plow
• name:  A surname (very rare: popularity rank in the U.S.: #37137)