noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A box containing a source of light and a white, translucent cover, used to view photographic transparencies.
2. 2
   A box containing fluorescent tubes or LED technology, used to treat people with seasonal affective disorder (SAD) and circadian rhythm disorders.
3. 3
   A kind of pop-up that is overlaid across a web page while the rest of the content is dimmed. Internet
4. 4
   A backbox.
5. 5
   A device used in phreaking that indicates when a telephone line is in use by means of a light.

Synonyms

All synonyms

backboxbackbox

Etymology

From light + box. In the Internet sense, originally the name of one specific technique.

Related phrases

circadian rhythmpop upseasonal affective disordertelephone lineweb page

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.