xū yào
to need
to want
to demand
to require
requirement
need
wǔ dì
Five Emperors from legendary times
possibly tribal leaders before the historiographers got working on them
usually taken to be Yellow Emperor 黃帝|黄帝[Huang2 di4] and four of his sons Zhuan Xu 顓頊|颛顼[Zhuan1 Xu1], Di Ku 帝嚳|帝喾[Di4 Ku4], Tang Yao 唐堯|唐尧[Tang2 Yao2], Yu Shun 虞舜[Yu2 Shun4]