What do people mean by "percent"

Cent is derived from the Latin "centum" which means "one hundred". In fact, cent is the root of many words. 

  • Century : one hundred years
  • Centipede: means "hundred footed one", but centipedes don't exactly have 100 legs
  • Bicentennial:  200 years
  • Centenarian: 100 year old person

The penny is one cent, which is 1/100th of a dollar. Likewise a centimeter is 1/100th of a meter.

When a word has "cent" at its root, it usually has to deal with 100. When someone says "percent" they mean "per one hundred", or something as proportion of one hundred.

Here is the exact definition of the word percent according to dictionary.com
https://www.dictionary.com/browse/percent?s=t