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

As the astronomical start of winter, today is the moment the sun reaches its lowest point in the sky as seen from Earth. —Daisy Dobrijevic, Space.com, 21 Dec. 2025

The winter solstice marks the beginning of astronomical winter in the Northern Hemisphere. —Julia Gomez, USA Today, 20 Dec. 2025

The scientist from Viseu, Portugal, had been working to explain the physics behind astronomical phenomena such as solar flares. —Kimberlee Kruesi, Fortune, 19 Dec. 2025

But despite an astronomical budget, James Cameron’s alien epic isn’t a blank-check fantasy where anything goes. —Alison Foreman, IndieWire, 19 Dec. 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