Optical

Part of speech: adjective

Pronunciation: /ˈɒptɪkəl/

Definitions

1. relating to vision, light, or the use of devices that assist in seeing
2. pertaining to sight, the behavior of light, or instruments designed for visual aid
3. associated with vision, the properties of light waves, or tools that enhance visual perception

Etymology: "Optical" is a straightforward formation: it is the adjective "optic" with the suffix "-al" added. The base "optic" comes from Greek "optikos", meaning "concerning sight", from the verb "optesthai", "to see" (the root of "-opsy" in medical terms). The English adjective is built directly on that Greek stem, so the word's core meaning has stayed fixed on seeing from the start. The suffix did most of the work over time. The "-al" ending descends from Latin "-alis", which Old French reshaped into "-el" and which reached Middle English as "-al", the same ending found in words like "national" and "musical". Adding it to "optic" turned a noun about the eye and vision into an adjective describing anything connected with seeing, light, or the instruments that aid it.

Synonyms: visual, ocular, seeing, sight-related, photonic

Antonyms: non-visual, invisible, blind, insensate, imperceptible