English Reference
adjective · noun

ultraviolet

adj. · n.
US /ˌəɫtɹəˈvaɪəɫɪt/ UK /ˌʊltɹɐvˈaɪələt/ ul·tra·vi·o·let

  1. 01 B2 Upper Intermediate Technical Science

    adj.describes light that has a higher frequency than the violet light we can see.

    adj.relating to electromagnetic radiation with wavelengths between approximately 10 and 400 nanometres, situated between visible light and X-rays.

    Simple

    You should wear sunscreen to protect your skin from harmful ultraviolet rays.

    In context

    The telescope was designed to detect ultraviolet emissions from distant stars that are otherwise obscured by interstellar dust.

    Usage

    Often used as a compound adjective with 'light', 'radiation', or 'rays'.

    UV
  2. 02 C1 Advanced Technical Science

    n.ultraviolet light or the part of the light spectrum that it belongs to.

    n.ultraviolet radiation or the region of the electromagnetic spectrum occupied by such radiation.

    Simple

    The scientist used a special lamp that produces ultraviolet to find the hidden marks.

    In context

    The atmosphere absorbs the majority of the sun's extreme ultraviolet, preventing the most energetic radiation from reaching the planet's surface.

    Usage

    Typically functions as an uncountable noun when referring to the radiation itself.

    UV radiation

Usage ultraviolet radiation · ultraviolet light

The bright light and ultraviolet radiation given off by the sun can lead to a condition known as "solar retinopathy".

BBC News· 13 Aug 2026

The UV Index (or UVI) is a measure of ultraviolet radiation used around the world.

BBC News· 22 Jun 2026

Etymology tree Proto-Indo-European *h₂el- Latin ūls Proto-Indo-European *-teros? Latin -ter Old Latin -ād Latin -ā Latin ultrālbor. English ultra- Latin viola Old French -ette Old French violettebor. Middle English violet English violet English ultraviolet From ultra- (“beyond”) + violet (“violet”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated