noun

• (uncountable) A weight class in professional boxing between light middleweight or welterweight and super middleweight or cruiserweight; a similar division in wrestling and other sports
• (countable) A boxer who fights in this division; a similar wrestler etc
• (by extension) A class in between heavy and light.
  "This would give the U.S. Army five parachute-capable brigades, or two "middleweight" infantry brigades, or six light infantry brigades, or six airmobile brigades in only two multicapable divisions."
• (countable, business, by extension) An employee ranking anywhere between junior and senior.
  "And it's interesting because in a way they're much more of a design company, and they've got their juniors and their seniors and their middleweights and all this stuff."