vanguard

The foremost position in an army or fleet advancing into battle.

The foremost or leading position in a trend or movement.

Those occupying a foremost position.

A detachment of an army whose duty it is to guard against surprise from the front and to clear the way; the van. Compare van.

To stand as a guard before.

The troops who march in front of an army; the advance guard; the van.

The leading units at the front of an army or fleet.

The person(s) at the forefront of any group or movement.

the position of greatest importance or advancement; the leading position in any movement or field