nón lưỡi trai

nón (“headwear”) +‎ lưỡi trai (“visor”).

• (Hà Nội) IPA^(key): [nɔn˧˦ lɨəj˦ˀ˥ t͡ɕaːj˧˧]
• (Huế) IPA^(key): [nɔŋ˦˧˥ lɨj˧˨ ʈaːj˧˧]
• (Hồ Chí Minh City) IPA^(key): [nɔŋ˦˥ lɨj˨˩˦ ʈaːj˧˧]

(classifier cái, chiếc) nón lưỡi trai

1. (Southern Vietnam, uncommon) a cap with visor

   Synonym: mũ lưỡi trai

• Vietnamese speakers would usually just use mũ or nón (depending on their dialect) when referring to most kinds of headwear in real life, so terms like this are often only used when distinction is needed, such as when making a purchase.