Definitions
1.nounA very large, heavy, or impressive person."an intellectual heavyweight"
2.nounThe professional boxing weight class for boxers weighing more than 190 pounds; a boxer in that division.
3.noun(uncountable) A similar division and contestant in other sports.
4.adjectiveOf the heavyweight boxing (or similar) division.
5.adjectiveBeing relatively heavy.
6.adjectiveBeing a leader in one's field.
7.adjectiveImportant or impressive.