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Definitions

idiopathic

[id-ee-uh-path-ik] / ˌɪd i əˈpæθ ɪk /
ADJECTIVE
primary
Synonyms
STRONGEST
constitutional dominant elementary essential fundamental immediate initial leading main prime principal underlying vital
STRONG
central chief first primitive simple
WEAK
direct earliest primal
Antonyms
STRONGEST
advanced auxiliary extra inessential inferior last minor nonessential secondary subordinate trivial unimportant
STRONG
sophisticated
ADJECTIVE
spontaneous
Synonyms
STRONGEST
casual impromptu instinctive offhand simple unplanned voluntary
WEAK
ad-lib automatic break loose down extemporaneous extempore free free-spirited from the hip impetuous improvised inevitable involuntary irresistible natural off top of head off-the-cuff unartful unavoidable unbidden uncompelled unconscious unconstrained uncontrived uncontrolled unforced unintentional unpremediated unprompted unsophisticated unstudied up front
Antonyms
STRONGEST
deliberate planned
WEAK
intended premeditated
ADJECTIVE
unknown
Synonyms
STRONGEST
anonymous exotic foreign nameless new remote strange uncharted undiscovered unexplained unexplored unfamiliar unidentified unnamed unrecognized
STRONG
X alien dark far secret
WEAK
concealed desolate distant far-off faraway hidden humble incog incognito little-known such and such unapprehended unascertained uncelebrated undistinguished unheard-of unnoted unperceived unrenowned unrevealed unsung untold
Antonyms
STRONGEST
common familiar identified known named native normal regular relevant usual
ADJECTIVE
idiosyncratic
Synonyms
STRONGEST
characteristic distinctive individual peculiar singular specific unique
STRONG
quirky
WEAK
personal
ADJECTIVE
individual
Synonyms
STRONGEST
lone original particular personal respective separate single singular sole special specific
STRONG
characteristic diacritic express solitary
WEAK
alone definite diagnostic different discrete distinct especial idiosyncratic indivisible odd only own peculiar personalized proper reserved secluded select several uncommon unique unitary unusual
Antonyms
STRONGEST
combined common general indefinite mixed normal ordinary together unimportant united usual

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It’s acquiring Centessa Pharmaceuticals, which is working on orexin receptor 2 agonists for conditions like narcolepsy and idiopathic hypersomnia — forms of daytime sleepiness.

From MarketWatch • Mar. 31, 2026

The company reported that the Tyvaso trial, TETON-1, showed a magnitude of improvement in treating idiopathic pulmonary fibrosis, or IPF, when compared with the first Phase 3 trial.

From Barron's • Mar. 30, 2026

The radio legend was diagnosed with idiopathic pulmonary fibrosis, a severe respiratory illness that can make breathing very difficult.

From BBC • Oct. 27, 2024

The young girl was diagnosed with juvenile idiopathic arthritis in March 2020.

From Los Angeles Times • Apr. 11, 2024

I went to school the next day and dramatically announced, “I have idiopathic craniofacial erythema!”

From "Insignificant Events in the Life of a Cactus" by Dusti Bowling

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.