磨光铁
磨光用铁

Rub \Rub\, n. [Cf. W. rhwb. See Rub, v,t,]
1. The act of rubbing; friction.

2. That which rubs; that which tends to hinder or obstruct
motion or progress; hindrance; obstruction, an impediment;
especially, a difficulty or obstruction hard to overcome;
a pinch.

Every rub is smoothed on our way. --Shak.

To sleep, perchance to dream; ay, there's the rub.
--Shak.

Upon this rub, the English ambassadors thought fit
to demur. --Hayward.

One knows not, certainly, what other rubs might have
been ordained for us by a wise Providence. --W.
Besant.

3. Inequality of surface, as of the ground in the game of
bowls; unevenness. --Shak.

4. Something grating to the feelings; sarcasm; joke; as, a
hard rub.

5. Imperfection; failing; fault. [Obs.] --Beau. & Fl.

6. A chance. [Obs.]

Flight shall leave no Greek a rub. --Chapman.

7. A stone, commonly flat, used to sharpen cutting tools; a
whetstone; -- called also {rubstone}.

{Rub iron}, an iron guard on a wagon body, against which a
wheel rubs when cramped too much.

{Rub of the green} (Golf), anything happening to a ball in
motion, such as its being deflected or stopped by any
agency outside the match, or by the fore caddie.
[1913 Webster + Webster 1913 Suppl.]