要素

yàosù
  1. essential factor
  2. key constituent

CEDICT

Entry Composition

1 要 yào
  1. to want; to need; to ask for
  2. will; shall; about to
  3. need to; should
  4. if (same as 要是 yàoshi)
  5. (bound form) important
2 素 sù
  1. raw silk
  2. white
  3. plain, unadorned
  4. vegetarian (food)
  5. essence
  6. nature
  7. element
  8. constituent
  9. usually
  10. always
  11. ever