stimulus (plural stimuluses or stimuli) An external phenomenon that has an influence on a system, by triggering or modifying an internal phenomenon; for example, a spur or incentive that drives a person to take action or change behaviour. quotations an economic stimulus Learn the meaning, pronunciation and usage of the word stimulus, which can be a noun for something that helps or produces a reaction. Find out how to use stimulus in different contexts, such as economics, biology and language. Stimulus is a lightweight JavaScript framework enhancing HTML with behavior, providing minimal code solutions for dynamic and interactive web applications. A stimulus is something that causes or elicits a response in an organism or a situation. Learn the different types, meanings, and uses of stimulus in various fields, such as psychology, physiology, and economics.