HSK C6
Correct

盟

/ méng / 
Strokes

Definition

oath/pledge/union/to ally/league, a subdivision corresponding to prefecture in Inner Mongolia

Example

As a Noun
ally; alliance
1
Xièméng
解盟

break off alliance (with)

As a Verb
pledge; swear; vow
As a Verb
become sworn brothers or sisters
As a Noun
league ［an administrative division of the Inner Mongolian Autonomous Region, corresponding to a prefecture］