Almost, nearly
This expression is used to indicate that some event or action almost happened but did not.
In most cases, it is used to express the speaker's relief that the event or action did not happen.
Because it refers to a past event, the form -(으)ㄹ 뻔했다 is always used.
It is often used together with the adverb 하마터면 and it only attaches to verbs.
This expression is often used following constructions that indicate hypothetical past situations such as -았/었으면 and -았/었더라면.
Indicate one's relief that a past event almost happened but did not.