Biennial

1. n. A plant which exists or lasts for two years.
2. a. Happening, or taking place, once in two years; as, a biennial election.
3. a. Continuing for two years, and then perishing, as plants which form roots and leaves the first year, and produce fruit the second.
4. n. Something which takes place or appears once in two years; esp. a biennial examination.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.