inhibit

Inhibit is a verb meaning to hold back, restrain, or prevent something from happening or advancing. The term derives from Latin inhibere, in- + habere, meaning to hold in or restrain. As a noun, inhibition refers to the act or process of restraining or the capacity to restrain.

In psychology, inhibition denotes cognitive or behavioral control that suppresses impulses or actions. Response inhibition is the ability to withhold a prepotent action. Social inhibition refers to reduced behavior in social contexts due to perceived scrutiny. Inhibition can be automatic or voluntary; the term appears in clinical descriptions of anxiety and impulse-control disorders.

In biology and biochemistry, inhibitors reduce the activity of enzymes, receptors, or other proteins. Enzymatic inhibition is categorized as competitive, noncompetitive, or uncompetitive, and can be reversible or irreversible. Competitive inhibitors bind the active site, noncompetitive inhibitors bind elsewhere, and uncompetitive inhibitors interact with the enzyme-substrate complex. Inhibition is a central mechanism in metabolic regulation and pharmacology.

In pharmacology and medicine, inhibitors are drugs that decrease or block physiological activity. They are characterized by kinetic parameters such as IC50, the concentration needed for half-maximal inhibition, and Ki, the dissociation constant. Examples include enzyme inhibitors, protease inhibitors, and receptor antagonists used to treat infections, cancer, hypertension, and neuropsychiatric conditions. In neuroscience, inhibitory signaling via GABA or glycine reduces neuronal excitability.

In everyday use, inhibit means to suppress or restrain actions, growth, or processes, and the term appears across science, medicine, law, and policy.