mustard seed

noun3

1. •
   A small, round seed of the mustard plant.
2. •
   (figurative) A small amount.

   • Start with a mustard seed of irrelevant fact. Rutherford Hayes’s wife, Lucy, was the first American president’s wife to be referred to as the first lady. — 2013
3. •
   [before a noun] Small lead shot, usually of size No. 12, used for shooting birds and other animals at close range.

   • Hmmmm... you suppose if you miss, you might blow a 1+1/2" hole anyway, with that rig? :) Even #9? 22rf shot (mustard seed) is supposed to be #12, not sure what that would do either. :/ — 2007