1. to
use up the last of or all of one's
resources in an attempt to succeed; to
obtain something (as by
necessity) from a poor
source. This expression may come from the idea that the material or food in the bottom of a barrel, such as one containing apples, would be the last (and sometimes of inferior
quality) of the entire batch. When one has used up all but those few apples at the bottom, he is forced to
use what is
left. 2. a
phrase used to mean to get to or
reach the lowest (
basic)
level attainable.