The Vietnamese word for hat is
mũ

Translations for hat and their definitions

mũ	©
1. n. (northern Vietnam) hat; cap; helmet
2. n. circumflex
3. prep. (arithmetic) to the power of
2 mũ 3 bằng 8 - 2 to the power of 3 is 8

nón	©
1. n. Asian conical hat
Chiếc nón kì diệu - The Amazing Conical Hat
2. n. (southern Vietnam, colloquial) hat; cap; helmet

Pronunciation