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

These expert picks start at just $8 at Amazon and could potentially save your life—or at the very least, save you serious money on astronomical ambulance and hospital bills. —Katie Jackson, Travel + Leisure, 7 Nov. 2025

Many farmers historically followed the almanac's advice, which often blended astronomical and folk-based knowledge with planting schedules. —Keith Matheny, Freep.com, 7 Nov. 2025

Operated by the European Southern Observatory (ESO), the VLT has long been at the forefront of astronomical discovery, as scientists use its cutting-edge technology to explore distant galaxies, and some, like our own Milky Way, that are closer to home. —Kenna Hughes-Castleberry, Space.com, 5 Nov. 2025

Deciphering these signals allowed researchers to study astronomical objects in the universe. —Gabriela Radulescu, The Conversation, 4 Nov. 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