woolsack

noun3

1. •
   A bag or bale of wool.

   • We shall never beat the French says one, why truly replied I, 'tis like kicking at a Woolsack—there is perpetual Resistance made, & a strange Elasticity […]. — 1794
2. •
   A seat made of wool; (specifically) the traditional seat of the British Lord Chancellor (since 2006 of the Lord Speaker of the House of Lords); hence (by metonymy) the post of Lord-Chancellor.

   • Well, Dick," rejoined Sir Wynston, merrily, "if both are to be fulfilled, or neither, I trust you may never sit upon the woolsack of England." — 1895
3. •
   Synonym of corestone.