What dictionary is that? Im American and even here we learned hecto means 100 in 1st grade.
Centi means 1/100th. (1) e.g. centifoot = 1/100th of a foot.
(1) https://dictionary.cambridge.org/dictionary/english/centi
Centi means 1/100th. (1) e.g. centifoot = 1/100th of a foot.
(1) https://dictionary.cambridge.org/dictionary/english/centi
The metric prefixes up to 1000 use Greek roots for the large prefixes (10^+n) and Latin for the small (10^-n), but there are also words that are derived directly from the respective Latin roots and therefore don't necessarily carry the metric system's fractional meaning.
Someone already linked to the definition of centimillionaire, but here are a few more:
* centipede (100 legs, not 1/100 of a leg)
* centenarian (100 years old, not 1/100 of a year old)
* millennium (1000 years, not 1/1000 of a year)