vanguard

/ˈvan-ˌgärd/

Middle English vauntgard, borrowed from Anglo-French vantgarde, avantgarde, from avant- "fore-" (from avant "before," going back to Late Latin abante) + garde

noun

  1. the forefront of an action or movement

  2. the troops moving at the head of an army

idiom

  1. in the position of the leaders of an action or movement in society, politics, art, etc.

They are at the vanguard of a revolution in medical research.

noun

  1. the soldiers, ships, etc., that are at the front of a fighting force that is moving forward