ex·​per·​i·​men·​tal | \ ik-ˌsper-ə-ˈmen-tᵊl How to pronounce experimental (audio) also -ˌspir- \

Definition of experimental

1 : of, relating to, or based on experience or experiment
2a : serving the ends of or used as a means of experimentation an experimental school
b : relating to or having the characteristics of experiment : tentative still in the experimental stage

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Other Words from experimental

experimentally \ ik-​ˌsper-​ə-​ˈmen-​tᵊl-​ē How to pronounce experimental (audio) also  -​ˌspir-​ \ adverb

Synonyms for experimental


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Examples of experimental in a Sentence

The fuel is being used on an experimental basis. an experimental procedure for patients suffering from leukemia
Recent Examples on the Web But some critics warn the government might be moving too fast, pushing an experimental vaccine on a broad populace in an effort to quickly regain lost tourist dollars. Washington Post, "Against the odds, Cuba could become a coronavirus vaccine powerhouse.," 29 Mar. 2021 The company was moving forward with an experimental COVID-19 vaccine. Sue Halpern, The New Yorker, "Why COVID-19 Vaccines Aren’t Yet Available to Everyone," 13 Mar. 2021 Last month, the company agreed to work with CureVac NV to help boost production of the German company’s experimental vaccine and improve the shot to help protect against multiple variants. Fortune, "Promising COVID-19 antibody therapy significantly reduces risk of hospitalization, death," 12 Mar. 2021 Their responses range from offshoring clinical trials to pursuing blood tests that could predict an experimental vaccine’s efficacy. Jared Whitlock, Wired, "The US Has 3 Covid Vaccines—Testing New Ones Is Complicated," 11 Mar. 2021 Despite being an experimental vaccine, Lamberski decided that vaccinating the safari park and zoo's apes was worth the risk, reports National Geographic. Elizabeth Gamillo, Smithsonian Magazine, "San Diego Zoo’s Great Apes Receive First Experimental Covid-19 Vaccine for Animals," 10 Mar. 2021 The Pfizer-BioNTech shot remains experimental because that final-stage study isn’t complete. Dallas News, "US panel endorses widespread use of Pfizer COVID-19 vaccine," 10 Dec. 2020 But the vaccine remains experimental while final testing is done. Lauran Neergaard And Danica Kirka, chicagotribune.com, "Pfizer’s coronavirus vaccine gets OK for emergency use in Britain," 2 Dec. 2020 But the vaccine remains experimental while final testing is done. Arkansas Online, "U.K. authorizes Pfizer coronavirus vaccine for emergency use," 2 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'experimental.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of experimental

15th century, in the meaning defined at sense 1

History and Etymology for experimental

Middle English, borrowed from Medieval Latin experīmentālis, from Latin experīmentum "testing, experience, proof" + -ālis -al entry 1 — more at experiment entry 1

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Time Traveler for experimental

Time Traveler

The first known use of experimental was in the 15th century

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Statistics for experimental

Last Updated

3 Apr 2021

Cite this Entry

“Experimental.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/experimental. Accessed 11 Apr. 2021.

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More Definitions for experimental



English Language Learners Definition of experimental

: relating to a scientific experiment or to scientific experiments in general
: made or done in order to see how well something works
: using a new way of doing or thinking about something


ex·​per·​i·​men·​tal | \ ik-ˌsper-ə-ˈmen-tᵊl How to pronounce experimental (audio) \

Kids Definition of experimental

: relating to, based on, or used for experiment He's trying an experimental treatment for the disease.


ex·​per·​i·​men·​tal | \ ik-ˌsper-ə-ˈment-ᵊl also -ˌspir- How to pronounce experimental (audio) \

Medical Definition of experimental

1 : of, relating to, or based on experience or experiment
2 : founded on or derived from experiment the heart of the experimental method is the direct control of the thing studied— B. F. Skinner
3 of a disease : intentionally produced especially in laboratory animals for the purpose of study experimental diabetes

Other Words from experimental

experimentally \ -​ᵊl-​ē How to pronounce experimental (audio) \ adverb

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