Observable

How to spell observable

10 letters · 4 syllables

How to pronounce observable

Say the part in capitals loudest.

What does observable mean?

1. adjectiveAble to be seen, noticed, or measured.

Observable in a sentence

• The new policy produced an observable drop in waiting times.

• There was no observable damage to the engine after the long drive.

Where does observable come from?

Language of origin: Latin

This word traces back to the Latin verb observare, which meant 'to watch over', 'to keep an eye on', or 'to attend to'. That verb was built from the prefix ob-, carrying a sense of 'towards' or 'over', joined to servare, meaning 'to watch, guard, or keep'. The same servare root sits behind such modern relatives as 'preserve', 'conserve', and 'reserve', all of which involve keeping or holding something. English took 'observe' from Old French observer in the late fourteenth century, and the adjective 'observable', meaning 'able to be seen or noticed', was formed by adding the productive Latin-derived suffix -able. Because that suffix attaches to a full verb form, the spelling keeps the -able ending rather than the -ible variant, which is the small trap to remember.

How the word is built

• ob- (towards, over)
• serv (from servare: to watch, keep)
• -able (capable of being)