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

• enormous
• immense
• oceanic

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

Captured by NOIRLab, this sunset reveals the pristine conditions that make Kitt Peak such a favorable astronomical site. —Kenna Hughes-Castleberry, Space.com, 31 Oct. 2025

These stone bowls were believed to have been used by Incan scholars for astronomical observations. —Ryan Knighton, AFAR Media, 31 Oct. 2025

His remarks add to ongoing debates about how space agencies handle public access to astronomical data, especially regarding rare interstellar visitors. —Hannah Parry, MSNBC Newsweek, 29 Oct. 2025

Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. —Big Think, 27 Oct. 2025

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