Definition of biennial :
1. A plant which exists or lasts for two years.
2. Continuing for two years, and then perishing, as plants which form roots and leaves the first year, and produce fruit the second.
3. Happening, or taking place, once in two years; as, a biennial election.
4. Something which takes place or appears once in two years; esp. a biennial examination.
- Slaves are besides brought occasionally from Wadai; and there is a biennial caravan from Wadai to Bengazi direct, leading to the coast a thousand and more slaves at once. - "Travels in the Great Desert of Sahara, in the Years of 1845 and 1846", James Richardson.
- No man can say why such a plant is annual, another biennial, and another endures for ages. - "An Essay on the Principle of Population", Thomas Malthus.
- In the annual and biennial plants, the root is worthless after the seed is ripe, and the stem also is of very little value; what virtue there is residing in the bark and leaves also lose their properties as fast as they lose their freshness. - "The American Reformed Cattle Doctor", George Dadd.