Definition

1. Adjective (Colloquial):
   • Absolutely certain; completely obvious; plain as day: Used to emphasize that something is undeniably true, clear, or incorrect. It carries a strong, often blunt, connotation of certainty, leaving no room for doubt or argument.

Usage Examples

• Adjective:
  • Sai đứt đuôi rồi, thôi đừng cãi nữa. (You are absolutely wrong, so stop arguing.)
  • Việc đó đứt đuôi là do anh ta gây ra. (It is as plain as day that he caused it.)

Advanced Usage

• The phrase can be used for strong, definitive emphasis in informal disputes or statements of fact. It often implies that further discussion is pointless because the truth is so evident.

Variants and Related Words

• Đứt đuôi con nòng nọc: A more vivid and emphatic variant meaning "as certain as a tadpole losing its tail." It intensifies the sense of absolute certainty.
  • Lỗi của anh ta rõ đứt đuôi con nòng nọc. (His mistake is as obvious as can be.)

Synonyms

• Absolutely certain
• Plain as a pikestaff
• Beyond a shadow of a doubt
• Patently obvious

Related Idioms

• Rõ như ban ngày: As clear as daylight (a less colloquial synonym for obviousness).
• Chắc như đinh đóng cột: As sure as nails in a post (a synonym for certainty).

1. (thông tục) Plain as a pikestaff
   • Sai đứt đuôi rồi, thôi đừng cãi nữa
     It is as plain as a pikestaff that you are wrong, so no use arguing on
   • Đứt đuôi con nòng nọc như đứt đuôi (ý mạnh hơn)