astronomical

adjective

as·​tro·​nom·​i·​cal ˌa-strə-ˈnä-mi-kəl 

variants or less commonly astronomic

ˌa-strə-ˈnä-mik 

1

: of or relating to astronomy

astronomical observations

2

: enormously or inconceivably large or great

astronomical numbers

an astronomical price

astronomically

ˌa-strə-ˈnä-mi-k(ə-)lē 

adverb

Synonyms of astronomical

• huge
• enormous
• vast
• tremendous
• gigantic
• massive
• giant
• colossal
• monumental
• immense
• mammoth
• bumper
• titanic
• mountainous
• cosmic
• planetary
• monstrous

Examples of astronomical in a Sentence

The cost of the office building was astronomical.

We got an astronomical telephone bill this month.

Recent Examples on the Web

One of the Mega Balls was taken away to make the astronomical odds of winning the jackpot slightly better, and the minimum prize amount a player could win was increased to $10. —Neal Riley, CBS News, 14 Apr. 2026

In the early 2000s astronomers analyzed the light from more than 200,000 galaxies using data from 2dF Galaxy Redshift Survey—a major astronomical project that mapped a large volume of the universe. —Manjishtha Bhattacharyya, Encyclopedia Britannica, 13 Apr. 2026

Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. —Big Think, 6 Apr. 2026

During the final week of March, Venus began setting after the end of astronomical twilight, that is, in a completely dark sky, a circumstance that will persist until late August. —Joe Rao, Space.com, 3 Apr. 2026

Word History

Etymology

Late Latin astronomicus "of or relating to astronomy" (borrowed from Greek astronomikós "of astronomy, skilled in astronomy," from astronomía astronomy + -ikos -ic entry 1) + -al entry 1

First Known Use

1551, in the meaning defined at sense 1

Phrases Containing astronomical

• astronomical unit

Rhymes for astronomical

• anatomical
• economical
• comical
• neuroanatomical
• uneconomical

Kids Definition

astronomical

adjective

as·​tro·​nom·​i·​cal ˌas-trə-ˈnäm-i-kəl 

variants also astronomic

-ˈnäm-ik 

1

: of or relating to astronomy

2

: extremely or unbelievably large

the cost was astronomical

astronomically

-ˈnäm-i-k(ə-)lē 

adverb