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

Meanwhile, the scale of the observable Universe continues to grow. —Big Think, 31 Mar. 2026

This dual-sensor setup improves tracking of low-observable or intermittently emitting targets. —Aamir Khollam, Interesting Engineering, 26 Mar. 2026

The committee felt the observable component gave UConn the edge. —CBS News, 16 Mar. 2026

Article continues below Many modern-day amateur telescopes come equipped with GoTo mounts, which automatically aim the optics at thousands of observable targets that are easily selected from pre-programmed astronomy catalogues. —Anthony Wood, Space.com, 14 Mar. 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