The forward part or surface
frontage, exterior, forepart, anterior, obverse, façade, bow, foreground, face, head, breast, frontal area, beginning.
Antonyms posterior, back, rear.
The fighting line
front line, van, no man's land, advance position, line of battle, vanguard, outpost, advance guard, firing line.
The appearance one presents before others
mien, carriage, bearing, port, demeanor, aspect, countenance, face, presence, expression, figure, exterior.
*Something assumed for show
façade, false front, mask, pretense, exterior, display, window dressing*; see also appearance 2, pose.
A person or group used to obscure activities
blind, cover, camouflage; see camouflage 1, disguise.