Emily Dickinson Lexicon

RUB, n.

1. The act of rubbing; friction.
2. That which renders motion or progress difficult; collision; hinderance; obstruction. Now every rub is smoothed in our way. Shak. Upon this rub the English ambassadors thought fit to demur. Hayward. All sort of rubs will be laid in the way. Davenant.
3. Inequality of ground that hinders the motion of a bowl. Shak.
4. Difficulty; cause of uneasiness; pinch. To sleep, perchance to dream; ay, there's the rub. Shak.
5. Sarcasm; joke; something grating to the feelings.