đảo

• (Hà Nội) IPA^(key): [ʔɗaːw˧˩]
• (Huế) IPA^(key): [ʔɗaːw˧˨]
• (Hồ Chí Minh City) IPA^(key): [ʔɗaːw˨˩˦]

Sino-Vietnamese word from 島 (“island”).

In the Dictionarium Annamiticum Lusitanum et Latinum (1651), there were several terms glossed as "island" (Portuguese ilha): cù lao, núi nước, gò nước, gò bẻ (i.e. gò bể), gò biẻn (i.e gò biển). Among these, only cù lao survived into current-day Vietnamese, although gò was still used to some extent until the early 20th century (see there for written example).

đảo itself is unattested in the Dictionarium Annamiticum Lusitanum et Latinum and has next to no attestation in Nôm prose and poetry aside from the literary proper noun 蓬島 (Bồng Đảo, “Penglai”) (although it is abundant in Chinese texts by Vietnamese writers). It is also not in Dictionarium Anamitico-Latinum (1838) nor even Đại Nam quấc âm tự vị (1895). In the former, the island of Côn Sơn is called hòn Côn nôn; in the latter, which is a dictionary chiefly based on Southern Vietnamese, the island of Phú Quốc is called hòn and cù lao.

It is not obvious when đảo started to become the chief word for "island" in Vietnamese, but it is probably not earlier than mid-19th century. By the early 20th century, đảo had become widely used in various texts.

(classifier hòn) đảo

1. island

Sino-Vietnamese word from 倒 (“to fall”).

đảo

1. to turn upside down; to flip over
2. to shake; to wag
3. (in compounds only) to fall