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

In Galaxy Mapper, author Allie Summers and illustrator Sian James introduce readers to French astrophysicist Hélène Courtois, a working scientist who studies cosmography, or mapping the observable universe. —Caroline Carlson, Literary Hub, 3 Nov. 2025

The species was once found south of the border in the Rio Sonoyta, but since groundwater pumping has depleted the river, there has been no observable population in the watershed. —John Leos, AZCentral.com, 30 Oct. 2025

After all, there are still around 1090 of them left over from the Big Bang within merely our observable Universe. —Big Think, 28 Oct. 2025

The Golden Gate Bridge had no observable damage but was located about 60 miles north of the quake’s epicenter. —Adrian Rodriguez, Mercury News, 27 Oct. 2025

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