An
expression combining the
English words
all and
but, which together have meanings such as "almost", or "very nearly", "to the point of, but not entirely." These should always be followed by a
verb or an
adjective which indicates a completed or extreme state.
Examples:
all but exhausted -- very, very tired
all but impossible -- very, very difficult
This expression dates back to the 1600's, when
English didn't really make a whole lot of sense. It is still in use 400 years later, when
English still doesn't make a lot of sense.