monad
/ˈmɒnæd/noun
1- technical a single unit; the number one〈技〉单一体。
1.1
- Philosophy (in the philosophy of Leibnitz) an indivisible and hence ultimately simple entity, such as an atom or a person【哲】（莱布尼兹哲学）单子（不可再分割的最简实体, 如原子或人）。
1.2
- Biology, dated a single-celled organism, especially a flagellate protozoan, or a single cell【生】〈旧〉单胞体（尤指鞭毛原生动物或单一细胞）。
派生词
monadic
adjectivemonadism
noun （Philosophy 【哲】）词源
early 17th cent.: via late Latin from Greek monas, monad- 'unit'， from monos 'alone'.