vanguard
van.guard \'van-.ga:rd\ n [ME vantgard, fr. MF avant-garde, fr. OF, fr. avant- fore (fr]. avant before, fr. L abante) + garde guard - more at ADVANCE 1: the troops moving at the head of an army 2: the forefront of an action or movement
Webster's English Dictionaryvan.guard \'van-.ga:rd\ n [ME vantgard, fr. MF avant-garde, fr. OF, fr. avant- fore (fr]. avant before, fr. L abante) + garde guard - more at ADVANCE 1: the troops moving at the head of an army 2: the forefront of an action or movement