boom3

 
Pronunciation: /buːm/

noun

  • 1a pivoted spar to which the foot of a vessel’s sail is attached, allowing the angle of the sail to be changed.
  • 2 [often as modifier] a movable arm over a television or film set, carrying a microphone or camera: a boom mike
  • 3a floating beam used to contain oil spills or to form a barrier across the mouth of a harbour or river.

Origin:

mid 16th century (in the general sense 'beam, pole'): from Dutch, 'beam, tree, pole'; related to beam