A period of exactly 100 years, or the anniversary of an event occurring 100 years after its original date.
From Latin 'centennium,' derived from 'centum' (hundred) + '-ennium' (a span of years). Parallel to 'biennium' (2 years), 'triennium' (3 years), and 'millennium' (1000 years).
Scientists studying long-term climate and geological patterns prefer 'centennium' over casual language because it's unambiguous—when you say 'century,' people might think 99 years, 100 years, or the 1900s all at once.
Complete word intelligence in one call. Free tier — 50 lookups/day.