In ancient times men were often sent on long garrison service far away.
Tips
usage
Mostly literary or historical: 戍守 (to garrison and defend) and 戍边 (to guard the frontier). Note the close look-alikes 戊 (a Heavenly Stem) and 戌 (an Earthly Branch); the inside mark differs.
The weapon frame, built on the dagger-axe 戈 (the indexing radical). It pictures a soldier holding a weapon to defend the border. Its strokes wrap around the inner dot.
The single dot inside stands in for the person on guard, distinguishing this character from the empty-framed 戊. It carries the idea of someone stationed at the post.