Heavyweight (noun)

1. A person or thing that is very heavy or large.
2. A boxer or wrestler who competes in a weight class above middleweight.
3. A person or thing that is very important or influential in a particular field.

Origin:

Heavyweight (n.) 1851, from heavy (adj.) + weight (n.).

Examples:

1. He was a heavyweight boxer.
2. She was a heavyweight in the field of computer science.
3. The package was a heavyweight.
4. He was a heavyweight champion.
5. She was a heavyweight in the industry.