experimental

adjective

ex·​per·​i·​men·​tal ik-ˌsper-ə-ˈmen-tᵊl 

also -ˌspir-

1

: of, relating to, or based on experience or experiment

2

a

: 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

experimentally

ik-ˌsper-ə-ˈmen-tᵊl-ē 

also -ˌspir-

adverb

Synonyms of experimental

• developmental
• investigative
• trial
• preliminary
• pilot

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

Shares of Merck have jumped 45% year to date as clinical trials for its investigational and experimental drugs continue to produce positive results. — Liz Napolitano, CNBC, 20 Aug. 2026

When Paul develops an experimental drug that improves communication, his obsession to see Theo speak threatens to destroy his family. — Andreas Wiseman, Deadline, 20 Aug. 2026

Moderna and Merck said Wednesday their experimental mRNA cancer vaccine successfully reduced recurrence of melanoma, and prevented the deadly skin cancer from spreading to other organs, in a large trial. — Peter Weber, TheWeek, 20 Aug. 2026

Eli Lilly, maker of Zepbound, said a study showed people on its experimental, next-generation weight-loss shot retatrutide achieved weight loss of 19% to 28%. — Ken Alltucker, USA Today, 20 Aug. 2026

Word History

Etymology

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

First Known Use

1526, in the meaning defined at sense 1

Phrases Containing experimental

• pre-experimental

Rhymes for experimental

• coincidental
• developmental
• environmental
• intersegmental
• nongovernmental
• transcontinental
• unsentimental
• accidental
• compartmental
• continental
• detrimental
• elemental

Kids Definition

experimental

adjective

ex·​per·​i·​men·​tal ik-ˌsper-ə-ˈment-ᵊl 

1

a

: of, relating to, or based on experience or experiment

experimental evidence

b

: subjected to the condition that is different from normal for a factor being tested in an experiment

the experimental group

2

: relating to or having the characteristics of experiment : tentative sense 1

still in the experimental stage

experimentally

-ᵊl-ē 

adverb

Medical Definition

experimental

adjective

ex·​per·​i·​men·​tal ik-ˌsper-ə-ˈment-ᵊl also -ˌspir- 

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

experimentally

-ᵊl-ē 

adverb