A word which means "military-like" or "authoritative looking"

Solution 1:

How about martial? It fits your first intended meaning of 'military-like'.

Solution 2:

Regimental comes to mind.

(need more letters to post.)

Solution 3:

If you're looking to describe an individual who is in the army, you could call them soldierly, though this doesn't carry the sort of authoritary nature you're looking for.

A commanding presence could be considered militaristically authoritative, though it's more used to express a power over someone, and not explicit military nature.

If the individual is a leader with absolute power, they could be autocratic, though again, not absolutely necessarily military. Similarly for magisterial.

And my final suggestion would be imperious, which today just means having an overbearing arrogance, but has its roots in being singularly powerful, such as in an empire.

Solution 4:

You could always use the adjective 'military-like'. If you use the adjective 'martial', or 'paramilitary', it might confuse the reader into thinking that the character is part of the military or a paramilitary. If you are describing clothes, you can also use 'military-style' or 'combat'.

Examples: "I bought some nice combat boots yesterday along with a military-style trenchcoat." "My teacher's goosestepping is military-like.