substantial

adjective

sub·​stan·​tial səb-ˈstan(t)-shəl 

1

a

: consisting of or relating to substance

b

: not imaginary or illusory : real, true

c

: important, essential

2

: ample to satisfy and nourish : full

a substantial meal

3

a

: possessed of means : well-to-do

b

: considerable in quantity : significantly great

earned a substantial wage

4

: firmly constructed : sturdy

a substantial house

5

: being largely but not wholly that which is specified

a substantial lie

substantial noun

substantiality

səb-ˌstan(t)-shē-ˈa-lə-tē 

noun

substantially

səb-ˈstan(t)-sh(ə-)lē 

adverb

substantialness

səb-ˈstan(t)-shəl-nəs 

noun

Synonyms

• significant
• major
• important
• historic
• big

Examples of substantial in a Sentence

A substantial number of people commute to work each day.

Activities like that pose a substantial risk of injury.

She purchased her tickets at a substantial discount.

Only the buildings that were constructed of more substantial materials survived the earthquake.

I was hoping that they would serve us something more substantial than wine and cheese.

Recent Examples on the Web

The heat exchanger is expected to be critical in regulating the substantial heat produced by hydrogen fuel cells, ensuring safety and efficiency in flight operations. —Kaif Shaikh, Interesting Engineering, 2 Oct. 2025

That is, people who have spent a substantial amount of time studying it, publishing research on it, teaching on it, or all of the above—for instance, pediatrician Peter Hotez, MD, PhD, on vaccines and nutrition scientist. —Erica Sloan, SELF, 2 Oct. 2025

Simply put, Cleveland’s roster was too expensive to make any substantial changes, which perhaps fans were looking for after the Cavs, for who knows how many years running, followed a strong regular-season campaign by falling short in the postseason. —Joe Vardon, New York Times, 2 Oct. 2025

Drugmakers already offer substantial discounts to Americans on Medicaid, and people covered by the program pay only a tiny co-pay for their prescriptions. —Nicholas Florko, The Atlantic, 2 Oct. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 2

Rhymes for substantial

• circumstantial
• insubstantial
• unsubstantial

Kids Definition

substantial

adjective

sub·​stan·​tial səb-ˈstan-chəl 

1

a

: consisting of or relating to substance : material

b

: not imaginary : real

the substantial world

c

: important sense 1, essential

substantial differences

2

: enough to satisfy and nourish

a substantial meal

3

a

: prosperous sense 1

a substantial farmer

b

: considerable in quantity : significantly large

a substantial increase

4

: firmly constructed

a substantial building

substantiality

-ˌstan-chē-ˈal-ət-ē 

noun

substantially

-ˈstanch-(ə-)lē 

adverb

Legal Definition

substantial

adjective

sub·​stan·​tial səb-ˈstan-chəl 

1

a

: of or relating to substance

b

: not illusory : having merit

failed to raise a substantial constitutional claim

c

: having importance or significance : material

a substantial step had not been taken toward commission of the crime

—W. R. LaFave and A. W. Scott, Jr.

2

: considerable in quantity : significantly great

identification of serious and substantial failure to perform

—U.S. Code

compare de minimis

substantiality

-ˌstan-chē-ˈa-lə-tē 

noun

substantially adverb