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

Stargazers will have to wait a few months for the next observable meteor shower activity. —Eric Lagatta, USA Today, 7 May 2026

Thus, dark matter could be a case of a single particle with two completely different observable behaviors, depending on its surroundings. —Paul M. Sutter, Scientific American, 6 May 2026

In turn, this helps researchers more accurately reproduce the observable universe. —Samantha Mathewson, Space.com, 6 May 2026

Space is the massive, ever-expanding realm beyond Earth’s atmosphere, spanning more than 93 billion light-years in the observable universe. —Georgina Jedikovska, Interesting Engineering, 27 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