significant

Use the adjective significant to describe something that is important. Your "significant other" means the person who's most important in your life. A significant result in a scientific study is a result large enough to matter.

A less common meaning of significant is to describe something that has a special or hidden meaning. A significant smile can convey feelings or information without words. This adjective is from Latin significans, from significare "to signify," from signum "a sign, mark" plus facere "to make."

Definitions of significant
1

adj rich in significance or implication

Synonyms:
meaning, pregnant
meaningful
having a meaning or purpose

adj important in effect or meaning

“a significant change in tax laws”
“a significant change in the Constitution”
“a significant contribution”
significant details”
“statistically significant
Synonyms:
important
important, of import
of great significance or value
meaningful
having a meaning or purpose
momentous
of very great significance
epoch-making, epochal
highly significant or important especially bringing about or marking the beginning of a new development or era
earthshaking, world-shaking, world-shattering
sufficiently significant to affect the whole world
evidential, evidentiary
serving as or based on evidence
fundamental, profound
far-reaching and thoroughgoing in effect especially on the nature of something
large
fairly large or important in effect; influential
monumental
of outstanding significance
noteworthy, remarkable
worthy of notice
probative, probatory
tending to prove a particular proposition or to persuade you of the truth of an allegation
operative
effective; producing a desired effect
portentous, prodigious
of momentous or ominous significance
Antonyms:
insignificant, unimportant
devoid of importance, meaning, or force
unimportant
not important
meaningless, nonmeaningful
having no meaning or direction or purpose
hole-and-corner, hole-in-corner
relating to the peripheral and unimportant aspects of life
flimsy, fragile, slight, tenuous, thin
lacking substance or significance
inappreciable
too small to make a significant difference
light
having little importance
superficial, trivial
of little substance or significance
show more antonyms...

adj fairly large

Synonyms:
substantial
considerable
large or relatively large in number or amount or extent or degree

adj too closely correlated to be attributed to chance and therefore indicating a systematic relation

“the interaction effect is significant at the .01 level”
“no significant difference was found”
Antonyms:
nonsignificant
attributable to chance

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