noun

• A short staff at a ship's bow, on which a jack is hoisted.

  ‘Navy ships not under way also hoist and lower the union jack on the jackstaff, at the ship's bow, and at morning and evening colors.’

  More example sentences

  • ‘Navy ships not underway fly the union jack on the jackstaff. The union jack is also flown from a yardarm to denote that a general court-martial is in session.’