observable

adjective

ob·​serv·​able əb-ˈzər-və-bəl 

1

: noteworthy

the trend is observable all over the country

2

: capable of being observed : discernible

the size of the observable universe

observability

əb-ˌzər-və-ˈbi-lə-tē 

noun

observable noun

observably

əb-ˈzər-və-blē 

adverb

Synonyms of observable

• visible
• visual
• noticeable

Examples of observable in a Sentence

the size of the observable universe

scientists often work with phenomena that are not directly observable

Recent Examples on the Web

As the average color of all the light from stars and galaxies in the observable universe, cosmic latte reflects the types of stars that are most common today. —Manjishtha Bhattacharyya, Encyclopedia Britannica, 13 Apr. 2026

Gasoline’s status as the observable, contentious price of transportation freedom has been universal for 45 years. —Ian Bogost, The Atlantic, 11 Apr. 2026

This ensures that, when inflation ends, the majority of entropy in the volume of the Universe that becomes our observable Universe comes from the end of inflation and the onset of the hot Big Bang. —Big Think, 9 Apr. 2026

Love has always been complicated—that’s why John Cassavetes’s movies are enduring landmarks of unpopular art, and why the Hays Code collapsed—but relationships were once, by consensus, straightforwardly observable on film. —Richard Brody, New Yorker, 7 Apr. 2026

Word History

Etymology

borrowed from Middle French & Latin; Middle French, "that must or can be observed," borrowed from Latin observābilis "capable of being observed," from observāre "to give attention to, watch carefully, observe" + -bilis "capable (of acting) or worthy of (being acted upon)" — more at -able

First Known Use

1589, in the meaning defined at sense 2

Rhymes for observable

• unobservable

Kids Definition

observable

adjective

ob·​serv·​able əb-ˈzər-və-bəl 

: able to be observed : noticeable

observably

-blē 

adverb