foot rule(n = noun.artifact) - a ruler one foot long;
is a kind of rule, ruler

N  measurement, admeasurement, mensuration, survey, valuation, appraisement, assessment, assize, estimate, estimation, dead reckoning, reckoning, gauging, horse power, metrology, weights and measures, compound arithmetic, measure, yard measure, standard, rule, foot rule, compass, calipers, gage, gauge, meter, line, rod, check, dividers, velo, flood mark, high water mark, Plimsoll line, index, scale, graduation, graduated scale, nonius, vernier, bathometer, galvanometer, heliometer, interferometer, odometer, ombrometer, pantometer, pluviometer, pneumatometer, pneumometer, radiometer, refractometer, respirometer, rheometer, spirometer, telemeter, udometer, vacuometer, variometer, viameter, thermometer, thermistor (heat) &c, barometer (air), anemometer (wind), dynamometer, goniometer, (angle) 244 meter, landmark, balance, scale, marigraph, pneumatograph, stethograph, rain gauge, rain gage, voltmeter (volts), ammeter (amps), spectrophotometer (light absorbance), mass spectrophotometer (molecular mass), geiger counter, scintillation counter (radioactivity), pycnometer (liquid density), graduated cylinder, volumetric flask (volume), radar gun (velocity), radar (distance), side-looking radar, (shape, topography), sonar (depth in water), light meter (light intensity), clock, watch, stopwatch, chronometer (time), anemometer (wind velocity), densitometer (color intensity), measurability, computability, determinability, coordinates, ordinate and abscissa, polar coordinates, latitude and longitude, declination and right ascension, altitude and azimuth, geometry, stereometry, hypsometry, metage, surveying, land surveying, geodesy, geodetics, geodesia, orthometry, altimetry, cadastre, astrolabe, armillary sphere, land surveyor, geometer, measuring, metric, metrical, measurable, perceptible, noticeable, detectable, appreciable, ponderable, determinable, fathomable, geodetical, topographic, topographical, cartographic, cartographical.

algorithmic rule, amp'8are foot, animal foot, as a rule, athlete's foot, australian hare's foot, bear's foot, best evidence rule, bird's foot, bird's foot clover, bird's foot trefoil, board foot, board rule, canary island hare's foot fern, candle foot, carpenter's rule, cat's foot, cleft foot, cloven foot, crow's foot, cubic foot, dove's foot geranium, exclusionary rule, flat foot, foot, foot brake, foot candle, foot doctor, foot dragging, foot guards, foot lever, foot pedal, foot pound, foot poundal, foot race, foot rot, foot soldier, foot ton, foot traffic, foot up, foot valve, fossorial foot, gag rule, goat's foot, golden rule, grammatical rule, ground rule, hand and foot, hearsay rule, heterodactyl foot, heuristic rule, home rule, horse's foot, human foot, immersion foot, invertebrate foot, linguistic rule, lion's foot, lobate foot, majority rule, metrical foot, miranda rule, mob rule, morphological rule, naegele's rule, one-man rule, parol evidence rule, phase rule, plumb rule, procrustean rule, rule, rule book, rule in, rule of cy pres, rule of evidence, rule of grammar, rule of law, rule of morphology, rule of thumb, rule out, slide rule, square foot, trench foot, tube foot, vertebrate foot, webbed foot, white-man's foot, whiteman's foot, work to rule, working rule, zygodactyl foot