inappropriate, unwelcome, and, typically, persistent behavior, as by an employer or co-worker, that is sexual in nature, specif. when actionable under federal or state statutes
See sexual harassment in American Heritage Dictionary 4
noun
The making of unwanted and offensive sexual advances or of sexually offensive remarks or acts, especially by one in a superior or supervisory position or when acquiescence to such behavior is a condition of continued employment, promotion, or satisfactory evaluation.