Defensible (adjective)

1. Capable of being defended, protected, or justified.
2. Capable of being defended against attack.

Origin:

From latin defendere, "to defend".

Examples:

1. The fortress was built on a high hill and had defensible walls.
2. The company's decision to cut jobs was not defensible.
3. The lawyer presented a defensible argument in court.
4. The castle was strategically placed in a defensible location.
5. The scientist's research findings were not defensible and were later debunked.