無窮小

无穷小
wúqióngxiǎo
  1. infinitesimal (in calculus)
  2. infinitely small

CEDICT

Entry Composition

1 無窮 wúqióng
  1. endless
  2. boundless
  3. inexhaustible
2 小 xiǎo
  1. small
  2. tiny
  3. few
  4. young

Related entries

無限小 wúxiànxiǎo
  1. infinitesimal
  2. infinitely small
無限小數 wúxiànxiǎoshù
  1. infinitesimal
  2. infinite decimal expansion
幾微 jīwēi
  1. tiny
  2. infinitesimal
微小 wēixiǎo
  1. minute (i.e. extremely small)
  2. infinitesimal
细菌微小到无法用肉眼看到。

Bacteria are so small that they cannot be seen with the naked eye.

Source: Tatoeba

極細小 jíxìxiǎo
  1. extremely small
  2. infinitesimal