Case law evidence shows that mental health professionals (MHPS) have lost cases in court because they based their professional action on the wrong definition of legal or ethical terminology. Many have also been sanctioned or their license revoked because of professional actions arising from a lack of clear understanding of these terminologies. This dictionary confronts this problem by providing MHPS with clear, concise, and functional definitions of many legal and ethical terminologies. A review of the meaning of these terms before a professional action or activity is sure to enhance compliance with ethical and legal standards and regulations. The addresses and phone numbers of state licensure boards for counselors, psychologists and social workers are included to facilitate consultation in related issues not specifically covered by definitions.