noun

• (mining) A fissure from which firedamp issues, often in quantity for many years.
  "The great sources of fire-damp in coal mines are blowers or fissures from which currents of this inflammable gas issue in considerable quantities and for a long series of years"
• (slang, chiefly British, New Zealand, Australia, Ireland, usually preceded by the) Telephone.
  "Get on the blower and call headquarters right away!"
• (slang, chiefly British, New Zealand, Australia, Ireland, usually preceded by the) Telephone.
• (dated) A braggart, or loud talker.
  "There hangs something majestic about a man who has borne his part in battles, especially if he is very quiet regarding it when you desire him to unbosom. I am continually lost at the absence of blowing and blowers among these old-young American militaires."