noun

• (also attributive, uncountable) Chiefly preceded by in or on: the state each year during which a male animal (usually a camel or an elephant) exhibits increased aggressiveness and sexual activity due to a high level of testosterone; (countable) an instance of this.
  "The Taroos, or elephant catchers, having marked down a wild herd of 300 or 400 elephants, the following preparations are made. About 200 Taroos collect together, mounted upon elephants, and accompanied by two large "taking elephants," highly fed, and kept always musth, (sensual) and when in that state their ferocity is such, that no one but their keeper dares to approach them. […] The active little Taroos now slide down from their steeds, and under cover of one of the musth elephants, who pushes himself forcibly against the wild one selected from the herd, they, in a most dexterous and daring manner, slip the moosack on to each of the hind legs, which performance occupies about three minutes."