Seen at a Teenagers' Club

If you have any doubt about what harass means or you can't imagine the Oxford Dictionary on your left says:

harass
/harrss, hrass/

• verb 1 torment (someone) by subjecting them to constant interference or intimidation. 2 make repeated small-scale attacks on (an enemy) in order to wear down resistance.

— DERIVATIVES harasser noun harassment noun.

— USAGE The word harass is pronounced either with the stress on the har- or with the stress on the -rass; the first pronunciation, which is the older one, is considered by some people to be the only correct one, especially in British English.

— ORIGIN French harasser, from harer ‘set a dog on’.