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

Now, External link products made substantially of steel, aluminum, and copper will pay a flat fee of 25% on their full value.

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

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

The Cheng visit is unlikely to substantially alter the substance of Trump’s meeting with Xi, said Ryan Hass, director of the John L. Thornton China Center at the Brookings Institution.

From The Wall Street Journal • Apr. 10, 2026

Since the Viking biology experiments were strongly oriented toward organisms that are comfortable in liquid water, some scientists held that the chance of Viking finding life would be substantially improved in Cydonia.

From "Cosmos" by Carl Sagan

Related Words

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