暗地裡

暗地里
àndìli
secretly; inwardly; on the sly

CEDICT

Entry Composition

1 暗地 àndì secretly; inwardly; on the sly
2 裡 lǐ
  1. lining
  2. interior
  3. inside
  4. internal
  5. also written 裏 lǐ