key log

Noun

 * 1) The log which, if removed, would free up the whole logjam.
 * 2) The key issue or problem, which if (re)solved, would make the current task easy to complete. The issue around which the whole problem revolves.
 * 3) * 1938, Col. Leonard P. Ayres, quoted in ""Cheapskate" Counterpoint", in Time magazine, Monday, Jan. 10, 1938
 * Present conditions are "a crisis of confidence. . . . Electric utilities are the key log."
 * Present conditions are "a crisis of confidence. . . . Electric utilities are the key log."