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
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"
place in a place where something cannot be removed or someone cannot escape; "The parents locked her daughter up for the weekend"; "She locked her jewels in the safe"
close with or as if with a tight seal; "This vacuum pack locks in the flavor!"