侗

dòng = du + (e)ng4

Dong ethnic group (aka Kam people)

侗

tóng = tu + (e)ng2

ignorant

侗 character breakdown

侗
- 亻
  - 丨
  - 丿
- 同
  - 冂
    - 丨
    - ㇆
      - 一
      - 亅
  - 𠮛
    - 一
    - 口

亻

rén = r + (e)n2

"person" radical in Chinese characters (Kangxi radical 9)

亻 = 丿 + 丨 : Mnemonic symbol: Rosa Luxemburg. She's quite radical, and her name starts with "r", just like "ren2". Also, 亻appears at the left-hand side of characters, and Rosa is a leftist as well.

Robinson Crusoe (r) and Rosa Luxemburg (亻) are having their favorite snacks in the encampment's kitchen: Rosa is eating a banana (丿) and Robinson is eating a dinosaur bone (丨).

同

tóng = tu + (e)ng2

like / same / similar / together / alike / with

同 = 冂 + 𠮛 : Tommy Turtle (tu) is stapling (冂) a magical scroll (𠮛) to the wall of the engine's kitchen ((e)ng2). On it he wrote that he's looking for two twins (mnemonic symbol for 同).

同

衕

tòng = tu + (e)ng4

see 衚衕|胡同[hu2 tong4]