Dictionary-enhanced plural guide
What is the Plural of “Stimulus”?
Learn the singular and plural noun forms, the rule behind the plural, and examples that show the form in context.
Singular and Plural Form of Stimulus
Stimulus is the singular noun form. Stimuli is the plural form.
Dictionary meaning: anything that triggers a reaction or causes something to happen or become more active
Why is the Plural of Stimulus “stimuli”?
The Irregular Plural Rule for Stimulus
This noun has an irregular plural form that does not follow standard English pluralization rules.
Plural pattern: irregular.
How to Remember the Plural of Stimulus
“stimulus” → “stimuli” is an irregular plural — there is no rule, so memorise the pair as a whole. Try writing it in 3 sentences today.
A common slip-up: STIM-uh-lus (with 'y' sound not clear) or STIM-you-lus (over-pronouncing the 'y').
Common Plural Mistakes with Stimulus
Wrong: The stimuluses affected the behavior significantly
Correct: The stimuli affected the behavior significantly
The correct Latin plural is stimuli, not stimuluses. Always use stimuli in formal and academic contexts
How to Pronounce Stimulus and Stimuli
Stress the first syllable: STIM-yuh-lus. The second syllable contains a light 'y' sound before the 'uh'
Other Words With the Same Plural Pattern as Stimulus
These nouns follow the same irregular rule. Click any word to see its plural page.
A young boy or girl who is not yet an adult.
the two parts at the bottom of your legs that touch the…
A tiny insect that lives around food and moves very fast.
One of two equal parts that make up something complete.
A grown-up male person. A man is an adult male, not a…
The ability to remember things from the past, or the thought you…
One human; a single individual.
Money that a person earns from their job, paid regularly by their…
Origin and Etymology of Stimulus
From Latin stimulus (goad, pointed stick for driving animals) — literally 'that which spurs on'
Cultural note: Stimulus package = government economic spending to boost a struggling economy. Used widely during 2008 and 2020 financial crises
Frequently Asked Questions About the Plural of Stimulus
What is the plural of “stimulus”?
The plural of “stimulus” is “stimuli”.
Is “stimuli” regular or irregular?
This page classifies it as irregular based on the available plural data.