thẳng

Most likely a loanword.

Its source is unclear; compare Middle Chinese 侹 (MC thengH) "long, level, straight (obsolete)" > Sino-Vietnamese thính.

The native Vietic word for "straight" is ngay, which also has Khmuic cognates.

• (Hà Nội) IPA^(key): [tʰaŋ˧˩]
• (Huế) IPA^(key): [tʰaŋ˧˨]
• (Saigon) IPA^(key): [tʰaŋ˨˩˦]

thẳng • (𣦎, 𣦛, 𥊢, 𥊣, 𬆅, 𬆈)

1. straight

   đứng thẳng ― to stand up straight