substantially

American  

[suhb-stan-shuh-lee] / səbˈstæn ʃə li /

adverb

1. by an ample or considerable amount; quite a lot.

   As a professor, my workload is substantially reduced or eliminated during the summer months.

2. in a basic or essential way; fundamentally.

   The new law mandates equal pay for substantially similar work, whether at the same establishment or not.

3. in a solid or firm way; stoutly or sturdily.

   In the far north, homes take more fuel to heat and also have to be built more substantially.

4. in a corporeal or material way; physically.

   The Eucharist makes the very Person of Christ truly, really, and substantially present in the consecrated bread and wine.

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Other Word Forms

• nonsubstantially adverb
• supersubstantially adverb

Etymology

Origin of substantially

substantial ( def. ) + -ly

Explanation

Substantially means "to a great extent." Your college fund was substantially increased by your grandfather's generous gift. What the heck, I'll throw in a quarter, too. Substantially is a good word to know any time you want to establish something's extent. It basically suggests "a large part." Your raise made your life substantially easier. The word also suggests an essential nature, as in "Nothing was substantially changed by the new law." The word carries a great deal of weight, as can be seen in this quote by Albert Einstein: "We shall require a substantially new manner of thinking if mankind is to survive."

Example Sentences

That said, workers’ willingness to pay for training did range substantially from some people seeing it as essential for their future employment, while others have zero willingness to pay for their own.

From Barron's • Apr. 14, 2026

The Big Garden Birdwatch survery, which has been carried out since the late 1970s, has shown that song thrushes and greenfinches have declined substantially.

From BBC • Apr. 13, 2026

Private equity investments suffer from inherent structural problems including limited disclosure, non-standardized return calculations that lack transparency, and management fees substantially higher than conventional investment funds.

From Los Angeles Times • Apr. 10, 2026

Nine biosimilars — which are FDA-approved drugs with the same safety, effectiveness and treatment benefits as the original drug — flooded the market at substantially lower prices.

From MarketWatch • Apr. 7, 2026

Her Creole had improved substantially, allowing her to take accurate notes as they described their various pains and miseries.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

Related Words

• considerably
• essentially
• extensively
• heavily
• largely
• materially
• really