noun
Botanical term for a plant that completes its life cycle within one year. Compare with 一年生植物 (いちねんせいしょくぶつ), a synonym also used in botany.
See also: 一年生植物
この花壇には一年草がたくさん植えてある。
Many annual plants are planted in this flower bed.
Annual plants need to be sown every year.
Perennial plant; lives for more than two years.
Biennial plant; completes its life cycle in two years.
Compound of 一年 (いちねん, 'one year') + 草 (そう, 'grass, plant').