Adverb

1. Contrary to what is expected; especially, of behavior different from what society expects.

   By going against the grain and going to work nude, you've made yourself a laughing stock.

2. To sand or plane a piece of wood parallel or nearly parallel to the fibers such that splinters forming ahead of the tool originate below the cutting surface
3. Unwillingly, reluctantly. It went much against the grain with him, i.e. it was much against his inclination, or against his pluck.
   • 1608, William Shakespeare, Coriolanus

     Say, you chose him / More after our commandment than as guided / By your own true affections, and that your minds, / Preoccupied with what you rather must do / Than what you should, made you against the grain / To voice him consul: lay the fault on us.