1.
a single hole, gap, or breach
A single opening or breach. The word is almost always used in the fixed proverb 蟻の一穴 — literally "an ant's single hole" — meaning a tiny flaw or oversight that leads to a catastrophic collapse.
一穴 literally means "a single hole" or "one opening," but it is almost never used outside the proverb 蟻の一穴.
Common expressions
- 蟻の一穴: "an ant's single hole [can bring down a great embankment]" — a tiny flaw or oversight that leads to a major disaster
Usage
The proverb comes from the image of a huge embankment being destroyed because water seeps in through one small ant hole. It warns that a small piece of carelessness, a minor security gap, or one overlooked detail can trigger large-scale failure, and is used across contexts such as engineering, business, and personal conduct.
Related Words
Related:
蟻 (ant)