Hostile (adjective)

1. Unfriendly and antagonistic.
2. Not conducive to life or growth; unfavorable.
3. Having or showing a desire to harm or fight someone.

Origin:

Late middle english: from old french hostil, from latin hostilis, from hostis "stranger, enemy".

Examples:

1. The two countries have a long history of hostile relations.
2. The environment in the desert was hostile to human life.
3. The hostile takeover bid was launched by a rival company.
4. He gave her a hostile look and walked away.
5. The soldiers faced hostile fire from the enemy.