English Reference
Noun

totality

n.
C1 Advanced US /toʊˈtæɫəti/ UK /təʊtˈælɪti/ to·tal·i·ty UK spelling totalities, totality's Astronomy

n.the whole amount or the entire collection of something. In astronomy, it refers to the complete amount of light or energy coming from an object.

n.the whole or entire amount of something; in an astronomical context, the total flux or luminosity of an object.


SIMPLE

The telescope measures the total light from the distant galaxy.

CONTEXTUAL

Astronomers calculated the total energy output of the supernova to understand its impact on the surrounding nebula.

COMPLEX

The study of the totality of cosmic microwave background radiation provides critical evidence for the early conditions of the universe following the Big Bang.

To experience the true marvel of the eclipse, one had to be in the path of totality – which this week crossed over Greenland, Iceland and Spain.

The Guardian· 13 Aug 2026

The length of the totality on land will make next year's eclipse remarkable, says Dr Ed Bloomer, an astronomer at the Royal Observatory Greenwich.

BBC News· 13 Aug 2026

Common in science writing


From total + -ity.

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

This entry
Level C1 · Advanced
Frequency Occasional
Updated