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

Other astronomical events in August include a Venus-Jupiter conjunction and the visibility of the Dumbbell Nebula. —Marina Johnson, The Courier-Journal, 7 Aug. 2025

The eventual winner will have to overcome astronomical odds of 1 in 292.2 million to win the Powerball jackpot. —Siladitya Ray, Forbes.com, 7 Aug. 2025

Where to visit in Michigan Scientists at observatories across Michigan study the Earth and astronomical phenomenon. —James Powel, Freep.com, 5 Aug. 2025

There was a time when people cared, gathering in front of the astronomical observatory, demanding answers. —Literary Hub, 4 Aug. 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