Heavyweight is a division, or weight class, in boxing. Fighters who weigh over 200 pounds (14 st 4 lb/90.7 kg) are considered heavyweights by the major professional boxing organizations: the International Boxing Federation, the World Boxing Association, the World Boxing Council, and the World Boxing Organization.
For most boxing organizations, the maximum weight for a cruiserweight is 200 pounds. Thus, a fighter whose weight is over 200 lb may not fight as anything but a heavyweight.
Read more about Heavyweight: Historical Development, Analogous Uses, Kickboxing