Rebuff (verb)

1. To reject or dismiss someone or something in an abrupt or ungracious manner.
2. To repel or ward off an attack or assailant.

Origin:

From french 'rebuffe', past participle of 'rebuffier', from old italian 'ribuffare' (to puff, puff back), from 'ri-' (back) + 'buffare' (to puff).

Examples:

1. She rebuffed his attempt to apologize for the argument they had earlier.
2. The company rebuffed the offer to buy their business, saying they were not interested in selling.
3. Despite their best efforts, the soldiers were unable to rebuff the enemy's advance.
4. He tried to rebuff the mosquitoes with his hand, but they kept biting him.
5. The castle walls were strong enough to rebuff the invaders' siege engines.