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Definitions

substantial

[suhb-stan-shuhl] / səbˈstæn ʃəl /
ADJECTIVE
important, ample
Synonyms
STRONGEST
big consequential considerable extraordinary generous hefty large massive meaningful serious significant sizable solid steady strong valuable vast
STRONG
material
WEAK
abundant big-deal bulky durable firm goodly heavy heavyweight key major-league momentous plentiful principal sound stable stout sturdy superabundant tidy weighty well-built worthwhile
Antonyms
STRONGEST
broken inconsiderable insignificant intermittent little meaningless miniature minor selfish slight small soft tiny trivial unimportant untrustworthy useless weak worthless
WEAK
ethereal impoverished mental poor spiritual unsubstantial
ADJECTIVE
material, real
Synonyms
STRONGEST
actual material positive real solid
WEAK
card-carrying concrete corporeal existent for real honest-to-God honest-to-goodness legit objective phenomenal physical righteous sensible sure-enough tangible true valid visible weighty
Antonyms
WEAK
ethereal impoverished insignificant little mental minor poor small spiritual unimportant unsubstantial
ADJECTIVE
rich
Synonyms
STRONGEST
solid
WEAK
affluent comfortable easy opulent prosperous snug solvent wealthy well well-heeled well-off well-to-do
Antonyms
WEAK
ethereal impoverished insignificant little mental minor poor small spiritual unimportant unsubstantial

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.

Formula One also has a substantial growth runway, they say, with the potential to significantly ramp up monetization for MotoGP, the world’s premier motorcycle racing championship.

From The Wall Street Journal • Apr. 3, 2026

Together, they create a cake that feels balanced — substantial enough to anchor a streusel, light enough to warrant a second slice.

From Salon • Mar. 31, 2026

France agreed to make an unspecified "substantial and continuing" contribution.

From BBC • Mar. 31, 2026

“While today’s news may be disappointing, we still believe Centurion will be a driver of substantial free cash flow and earnings growth for Peabody over the medium/longer term,” Jefferies analysts wrote.

From Barron's • Mar. 30, 2026

I had rarely felt it before, and never for anything substantial.

From "We Are Okay" by Nina LaCour

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