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

This discovery also suggests that astronomical events were observed by people outside of the elite class and state control. —Maria Mocerino, Interesting Engineering, 11 Oct. 2025

The brightness Pettit observed is one of the worries, as these Starlink trains — usually most apparent shortly after launch aboard SpaceX’s Falcon 9 rocket — can interfere with astronomical observations. —Elizabeth Howell, Space.com, 10 Oct. 2025

The winter solstice is the start of astronomical winter, when Earth's northern hemisphere is pointed the farthest away from the sun due to its tilted axis. —Sarah Moore, Freep.com, 9 Oct. 2025

As always, this astronomical event is best viewed from a dark sky area. —Lydia Price, Travel + Leisure, 8 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