observable

adjective

ob·​serv·​able əb-ˈzər-və-bəl 

1

: noteworthy

2

: capable of being observed : discernible

observability

əb-ˌzər-və-ˈbi-lə-tē 

noun

observable noun

observably

əb-ˈzər-və-blē 

adverb

Synonyms

• apparent
• seeable
• visible
• visual

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

This cosmic trip back in time revealed that the observable universe extends for almost 50 billion light-years in all directions around us. —Robert Lea, Space.com, 18 Mar. 2025

The team has measured that the observable universe extends close to 50 billion light years in all directions, and has as much mass as close to 2 trillion trillion suns. —Dan Perry, Newsweek, 18 Mar. 2025

In the longer term, autonomous offensive forces might be inserted by low observable aircraft or submarines and left behind with small or no human crews. —Stephen Peter Rosen, Foreign Affairs, 14 Mar. 2025

The cycling experience is like the observable universe. —Rob Reed, Forbes, 11 Mar. 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