semicentennial

adjective [原级]五十周年纪念的；五十年一度的

In this process, Surrealism became the genre which acted the longest time in the Western Modern Style Art by right of semicentennial life.
在这个过程中，超现实主义绘画凭借半个世纪的寿命成为现代派美术里活动时间最长的一个流派。