any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention
the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle; "nerve impulses cross a synapse through the action of neurotransmitters"
a major part of the central nervous system which conducts sensory and motor nerve impulses to and from the brain; a long tubelike structure extending from the base of the brain through the vertebral canal to the upper lumbar region
doing something in opposition to another way of doing it that you don't like; "his style of painting was a reaction against cubism"
a bodily process occurring due to the effect of some foregoing stimulus or agent; "a bad reaction to the medicine"; "his responses have slowed with age"
an idea evoked by some experience; "his reaction to the news was to start planning what to do"
extreme conservatism in political or social matters; "the forces of reaction carried the election"
a response that reveals a person's feelings or attitude; "he was pleased by the audience's reaction to his performance"; "John feared his mother's reaction when she saw the broken lamp"
(mechanics) the equal and opposite force that is produced when any force is applied to a body; "every action has an equal and opposite reaction"
disease or disability resulting from conditions of employment (usually from long exposure to a noxious substance or from continuous repetition of certain acts)