Defensive — Defs

01 a. Serving to defend or protect; proper for defense; opposed to offensive; as, defensive armor.

1.
Serving to defend or protect; proper for defense; opposed to offensive; as, defensive armor.
“A moat defensive to a house.” — Shak.
2.
Carried on by resisting attack or aggression; -- opposed to offensive; as, defensive war.
3.
In a state or posture of defense.

02 n. That which defends; a safeguard.

1.
That which defends; a safeguard.
“Wars preventive, upon just fears, are true defensives.” — Bacon.

Phrases & compounds

To be on the defensive — to be or stand in a state or posture of defense or resistance, in opposition to aggression or attack.