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

At the core of the design process was a substantial allocation of computing time on ORNL’s Summit supercomputer. —Aman Tripathi, Interesting Engineering, 25 Sep. 2025

But Niccol said this larger-scale effort is more substantial. —Jordan Valinsky, CNN Money, 25 Sep. 2025

This announcement further strengthens the relationship between OpenAI and Nvidia as leaders at the forefront of the AI revolution, while providing OpenAI with substantial funding at lower costs by reducing its credit risk, Wedbush Securities analysts wrote in a Tuesday note to investors. —Sheryl Estrada, Fortune, 24 Sep. 2025

Eager to rebuild the town’s economy and despite Kiehn’s decision to hire former Nazi Party friends and colleagues, Trossingen’s city councilors welcomed him with open arms and provided him with a substantial grant to rebuild his businesses. —Robert M. Ehrenreich, JSTOR Daily, 24 Sep. 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