The word "centiday" is spelled as /ˈsentədeɪ/. It is composed of "centi-" meaning one hundredth and "-day" which pertains to a 24-hour period. Thus, a centiday is equivalent to one hundredth of a day or 14.4 minutes. This unit of time is not commonly used in everyday life but is often employed in scientific and engineering applications, particularly in the study of light and the measurement of radiation exposure.
The word centiday does not have an established etymology, as it is not a commonly used term in the English language. It seems to be a combination of the prefix centi- meaning one hundredth, and the word day.