1. (n.) One who rules; one who exercises sway or authority; a governor.

2. (n.) 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).

A per se T square ace anointed king birch boss cane captain castellan champion chatelain chatelaine chief chieftain club commandant commander crowned head dean director dynast emperor executive ferule fugleman genius governor grand duke head high chief higher-up imperator intendant king king-emperor kinglet laureate leader lord paramount majesty manager master monarch nonpareil overlord paddle pandybat paragon paramount petty king potentate prince prince consort principal prodigy rattan rod royal royal personage royalty rule senior sovereign square star stick straightedge superior superman superstar suzerain switch tetrarch the greatest the most top dog triangle virtuoso