noun

• (UK, slang) Unpleasant odour.
• (dated) An imposition or hoax; humbug.
• (obsolete) A kind of strong drink.
  "you do provide me hum enough , And lour to bouse with"
• (with article) A phenomenon, or collection of phenomena, involving widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise not audible to all people.
  "There is a range of theories from farm or factory machinery to conspiracy theories such as flying saucers. And yet, "the hum" remains an unsolved case."

verb

• (intransitive) To make a sound from the vocal cords without pronouncing any real words, with one's lips closed.
  "We are humming happily along with the music."
• (transitive) To express by humming.
  "to hum a tune"
• (intransitive) To drone like certain insects naturally do in motion, or sounding similarly.
  "The leaves of the foreſt were loaded with manna, pure amber dropped from every bough, honey diſtilled from the rifted rock, and the humming bee, drunk with joy, ſtrayed from flower to flower, forgetful of his burſting cells."
• (intransitive) To buzz, be busily active like a beehive
  "The streets were humming with activity."

noun

• (informal, Malaysia, Singapore) Synonym of see hum (“blood cockles, ark clams”).

noun

• (bridge) Initialism of highly unusual method: any of a class of contract bridge bidding systems that require advance preparation to contend with, and are usually restricted to the highest levels of tournament play.