noun pl. centuries -·ries

1. any period of 100 years, as from 1620 to 1720
2. a period of 100 years reckoned from a certain time, esp. from the beginning of the Christian Era ( 1) [ 1 through 100 is the first century; 1801 through 1900 is the 19th century; 400 through 301 is the 4th century]: in common usage, a century begins with a year ending in 00 and runs through 99, as 1800-1899
3. in ancient Rome
   1. a military unit, originally made up of 100 men
   2. a subdivision of the people made for voting purposes
4. a series, group, or amount of a hundred

Etymology: L centuria < centum, hundred