Observable

Part of speech: adjective

Pronunciation: /əbˈzɜː.və.bəl/

Definitions

1. Capable of being seen, noticed, or detected through direct examination or measurement
2. Able to be seen or otherwise noticed by observation or measurement
3. Visible or identifiable through direct inspection or sensory experience

Etymology: "Observable" is a plain case of an English adjective built from a verb plus a suffix. The verb "observe" comes from Latin "observare," meaning to watch, keep, or pay heed to, and the suffix "-able" traces back through Old French and Latin "-abilis," which marked something capable of being done or undergoing an action. Put together, "observable" describes whatever can be watched, noticed, or measured. The suffix itself has a long lineage. Its Latin form "-abilis" was attached to verb stems to make adjectives, and Old French carried that pattern into the language that later entered Middle English, where "-able" became a productive ending that English speakers could attach to nearly any suitable verb. This is why English can generate new adjectives of this kind so readily.

Synonyms: noticeable, perceptible, discernible, detectable, visible

Antonyms: invisible, unnoticeable, indiscernible