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

The gas giant makes for a dazzling astronomical target when viewed with the naked eye, which only gets more impressive when viewed through a telescope with an aperture of 4-inches (152 mm) or more, which helps reveal its colorful atmospheric cloud bands. —Anthony Wood, Space.com, 9 Jan. 2026

How Vinyl Records Are Valued Sentiment aside, some rare vinyls have unspeakable financial value and have sold for astronomical prices at auctions. —Lauren Wellbank, Martha Stewart, 9 Jan. 2026

The new year marks the beginning of a spectacular streak for the astronomical phenomenon, which will be longer-lasting and better positioned than ever before. —Lydia Price, Travel + Leisure, 9 Jan. 2026

But if agencies can keep astronomers’ ambitions from becoming too astronomical, while taking full advantage of the new design space opened up by the superheavy-lift rockets, then our understanding of the universe could advance beyond imagination in just a decade or so. —Martin Elvis, The Conversation, 9 Jan. 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