From The Collaborative International Dictionary of English v.0.48:
Ruler \Rul"er\ (r[udd]l"[~e]r), n.
1. One who rules; one who exercises sway or authority; a
governor.
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And he made him ruler over all the land. --Gen. xli.
43.
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A prince and ruler of the land. --Shak.
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2. A straight or curved strip of wood, metal, etc., with a
smooth edge, used for guiding a pen or pencil in drawing
lines. Cf. Rule, n., 7
(a) .
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Parallel ruler. See under Parallel.
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