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Definitions

mysterious

[mi-steer-ee-uhs] / mɪˈstɪər i əs /
ADJECTIVE
obscure, puzzing, suggesting a mystery
Synonyms
STRONGEST
baffling cryptic curious dark enigmatic inexplicable inscrutable magical mystical mystifying obscure perplexing puzzling secretive strange unknown weird
WEAK
abstruse alchemistic arcane astrological cabalistic covert difficult eldritch enigmatical equivocal esoteric furtive hidden impenetrable incomprehensible insoluble necromantic occult oracular recondite sphinxlike spiritual subjective symbolic transcendental uncanny unfathomable unknowable unnatural veiled
Antonyms
STRONGEST
apparent bright clear comprehendible comprehensible evident familiar intelligible known normal obvious plain regular usual visible
WEAK
public straightforward tangible unmysterious

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.

The mysterious arson fires in a Hollywood neighborhood started small.

From Los Angeles Times • Apr. 1, 2026

So the Sora video-generating app was canceled, and my guess is the Atlas browser—plus a mysterious hardware device by designer diva Jony Ive—may be the next to be killed.

From The Wall Street Journal • Mar. 29, 2026

Ursula has shades of Gellar’s famous characters — Buffy’s physical ferocity, Kathryn Merteuil’s ruthless cattiness, Daphne Blake’s affinity for mysterious games — but doesn’t play to one exclusively.

From Salon • Mar. 26, 2026

Researchers have uncovered how a mysterious ion channel helps cells break down waste, opening new possibilities for treating Parkinson's disease.

From Science Daily • Mar. 26, 2026

Last night George had eaten two plates of roast beef, veal and ham pie, carrots sweet as candy, and a mysterious dessert called meringue pudding.

From "I Survived the Sinking of the Titanic, 1912" by Lauren Tarshis