Straightedge(n.) A board, or piece of wood or metal, having one edge perfectly straight, -- used to ascertain whether a line is straight or a surface even, and for drawing straight lines.
Thesaurus Entries
Aristotelian sorites, Goclenian sorites, Procrustean law, SOP, T square, a priori truth, acme, act, act on, administration, antetype, antitype, apothegm, appointment, apriorism, archetype, as a rule, ascendancy, assize, authority, authorization, average, axiom, balance, ban, bar, barometer, be in, be in force, be the rage, be the rule, be the thing, be-all and end-all, bear reign, bid, bill, biotype, blue ribbon, brevet, brocard, bull, bylaw, bypass, call on, call the shots, call the signals, call upon, canon, carry authority, categorical syllogism, center, championship, charge, charisma, charm, check, chiefly, civil government, classic example, claws, clout, clutches, code, command, commandment, commission, common practice, commonly, conclude, condemn, consequence, control, convention, crack the whip, credit, criterion, customarily, customs, decide, declaration, declare, decorum, decree, decree-law, decreement, decretal, decretum, deduce, deem, degree, determine, dictate, dictation, dictum, diktat, dilemma, direct, direction, directive, directorship, discipline, dismiss, dispensation, dispose, disposition, disregard, dominance, dominate, domination, domineer, dominion, doom, drill, edict, edictum, effect, effectiveness, eliminate, eminence, empery, empire, enactment, enchantment, enjoin, enthymeme, epitome, esteem, etiquette, exclude, fact, favor, fiat, figure, find, find against, find for, first place, first prize, forbid, force, form, form of government, formality, formula, formulary, fugleman, fugler, fundamental, gather, gauge, general orders, general principle, generality, generally, genotype, give an order, give the word, gnome, golden mean, golden rule, good feeling, govern, governance, government, graduated scale, grip, guide, guideline, guiding principle, hand, hands, happy medium, have clout, have power, have the power, have the right, have the say, head up, headship, hegemony, height, highest, hold, ignore, imitatee, imperative, imperium, importance, in the main, incidental power, infer, influence, influentiality, insinuation, institution, instruct, instruction, ipse dixit, iron hand, issue a command, issue a writ, judge, jurisdiction, jus, juste-milieu, kingship, law, law of nature, lay off, lay out, lead, leadership, legislation, leverage, lex, lordship, magnetism, mainly, manage, management, mandate, mark off, mark out, mastership, mastery, matter of course, maxim, maximum, mean, measure, measure off, measure out, median, mediocrity, medium, middle, middle course, middle ground, middle point, middle position, middle state, middle-of-the-road, midpoint, mirror, mitzvah, mode, model, modus tollens, moment, mood, moral, most, mostly, ne plus ultra