n. van·guard

Pronunciation: \ˈvan-ˌgärd
Function: noun

Etymology:
Middle English vauntgard, from Anglo-French vantgarde, avantgarde, from avant- fore- (from avant before, from Late Latin abante) + garde guard -

Date:
15th century

1 : the troops moving at the head of an army
2 : the forefront of an action or movement