Webster's Revised Unabridged Dictionary · 1913

Neurosis

Neurosis , noun

[New Latin, from Greek ney^ron nerve.]

1.
(Medicine) A functional nervous affection or disease, that is, a disease of the nerves without any appreciable change of nerve structure.
2.
(Psychiatry) a mental or emotional disorder that affects only part of the personality, and involves less distorted perceptions of reality than a psychosis. As used in medicine, anxiety is a prominent characteristic, and the condition may be accompanied by psychosomatic symptoms. Phobias and compulsive behavior are common varieties. — [MW10]