Inhibition: the process by which some cells use their terminals to stop the receiving cells from relaying information. (Kandel, 71) The cessation of an activity. Some neurons function primarily to inhibit other neurons. (Kolb, 66-67)

Nerve cells use their “presynaptic terminals” to stop the (post synaptic neurons) from relaying information. A stable, predictable, coordinated response to a particular “stimulus.” (Doidge, 71) The balance between "excitatory" and inhibitory inputs to a neuron determines whether it will "fire." (LeDoux, 51) Some drugs inhibit (and some enhance) the release of a particular “neurotransmitter” molecule and thus influence the “synaptic transmission” process. (The Brain-Leslie Iversen, 78-79) A very useful device in neural circuits. It adds tremendously to the specificity of information processing, filtering out random excitatory inputs, preventing them from triggering activity. (LeDoux, 52) Verb - ‘inhibit.’ Adverb - ‘inhibitory.’ Also referred to as ‘suppression.’ Editor’s note - may apply to a neuron, a “synapse,” a “signal,” a neurotransmitter, a “protein receptor,” or a “gene."

Inhibitor: in chemistry and biochemistry - a substance which slows down or prevents a particular reaction or process, or diminishes the activity of some “reactant” or “catalyst”. In genetics, a gene whose presence prevents the “expression” of some other gene at a different “locus.” (Oxford)

Inhibitory Interneuron: releases a "transmitter" from its terminal that decreases the likelihood that the “postsynaptic cell” will fire. These neurons play an important role in counterbalancing the excitatory activity of other neurons. They are often firing all the time. Can be thought of as ‘filters.’ (LeDoux, 50-51) 

Inhibitory Neurotransmitter: one released from the presynaptic neuron whose work increases the “resting membrane potential” of the postsynaptic neuron from -70 to -75 millivolts making it much more difficult for the neuron to fire. (Kandel, 98) A signal that inhibits a neuron. When a neuron receives enough inhibitory signals from other neurons, it becomes less likely to fire. (Doidge, 54) Also referred to as 'inhibitory signal.'

Inhibitory Receptor: receptors determine whether the synaptic action will be excitatory or inhibitory by controlling different "ion channels" in the “cell membrane,” primarily "sodium" for excitation, and “chloride” for inhibition. (The Brain-Eric Kandel, 30) Editor's note - for example, a “GABA receptor.” 

Inhibitory Synapse: indicates a synapse that “hyperpolarizes” its target, decreasing the chance that the neuron will fire an action potential. (Kandel, 440)