any of a class of variable stars with regular cycles of variations in luminosity (most ranging from three to fifty days). There is a relationship between the periods of variation and the absolute magnitudes, which is used for measuring the distance of such stars
Cepheid variable in American English
noun
Astronomy
a variable star in which changes in brightness are due to alternate contractions and expansions in volume
Also: cepheid variable
Word origin
[1900–05; cephe(us) + -id1]This word is first recorded in the period 1900–05. Other words that entered Englishat around the same time include: desensitize, elder statesman, geopolitics, hormone, hydroplane-id is a suffix of nouns that have the general sense “offspring of, descendant of,” occurringoriginally in loanwords from Greek (Atreid; Nereid), and productive in English on the Greek model, esp. in names of dynasties, withthe dynasty’s founder as the base noun (Abbasid; Attalid), and in names of periodic meteor showers, with the base noun usually denoting theconstellation or other celestial object in which the shower appears (Perseid)