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

New Section 232 tariffs impose a 25% flat fee on the full value of products substantially made of steel, aluminum, and copper.

From Barron's • Apr. 15, 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

By age 67, even accounting for inflation, your portfolio could grow substantially.

From MarketWatch • Apr. 10, 2026

“We have known for decades that once you have one disc surgery, the chances of having another are substantially higher, especially if you use the fusion technique like Tiger. It’s a domino effect.”

From Los Angeles Times • Apr. 8, 2026

On the “happy” segments inserted for comparison purposes, he scored 14.13, which was substantially lower than both Rather and Brokaw.

From "The Tipping Point" by Malcolm Gladwell

Related Words

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