1) a mental illness that makes a person refuse to eat (anorexia)

2) (of) a person sexually attracted to people of her or his won sex described in medical textbooks as mental illness (homosexual)

3) a serious mental illness causing great excitement, violence (mania)

4) a mental illness in which a person has exaggerated ideas of her or his importance, power, wealth etc (megalomania)

5) a mental illness with anxiety, excited behaviour, abnormal concern etc caused by disorders of the nervous system or by something in the subconscious mind (neurosis)

6) a mental illness marked by fixed delusions, e.g. of persecution (paranoia)

7) the method of treating some mental illness by looking at and discussing the effects of events in the patient's life as possible causes (psychoanalysis)

8) a kind of mental illness producing a loss of sense of what is true or real, and emotional difficulties, antisocial behaviour etc (schizophrenia)