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 of substantial

• 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

Although the study was designed primarily to establish safety, almost all of the participants reported substantial improvements in their symptoms for at least a month. —Clayton Dalton, New Yorker, 13 Mar. 2026

Trading commodities, futures, and options involves a substantial risk of loss. —Usa Today, USA Today, 12 Mar. 2026

The company's lawyer, Paul Schmidt, said earlier this month that the core question in the case is whether the platforms were a substantial factor in Kayley's mental health struggles. —ABC News, 12 Mar. 2026

Lawmakers have reduced that share significantly over the years, starting with a substantial cut from the 10% level that persisted prior to 2011 when lawmakers significantly increased the income tax. —The Editorial Board, Chicago Tribune, 12 Mar. 2026

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