noun

• (figurative) Importance or influence.
  "I liked the man for his own sake, and even had he promised to turn out a celebrity it would have had no weight with me. I look upon notoriety with the same indifference as on the buttons on a man's shirt-front, or the crest on his note-paper."
• (weightlifting) An object, such as a weight plate or barbell, used for strength training.
  "He's working out with weights."
• (lubricants) Viscosity rating.
• (physics) Mass (atomic weight, molecular weight, etc.) (in restricted circumstances).

verb

• (transitive) To add weight to something; to make something heavier.
• (transitive) To add weight to something; to make something heavier.
• (transitive) To load, burden or oppress someone.
• (transitive, mathematics) To assign weights to individual statistics.