Harass (verb)

1. To subject to aggressive pressure or intimidation.
2. To subject repeatedly to unwanted or annoying actions.
3. To create an unpleasant or hostile situation for (someone) by uninvited and aggressive actions.
4. To annoy or torment persistently.
5. To wear out by constant attack.

Origin:

French harceler, from harer to set a dog on, from hare, noun.

Examples:

1. The company harassed its competitors.
2. She was harassed by phone calls at all hours of the night.
3. The dog harassed the mailman.
4. The company harassed the employees with unreasonable demands.
5. The enemy harassed the town with raids.