rule رزن razan Fr.: règle A law or regulation that governs behaviors, actions, or operations.
→ Arnett’s rule, → commutation rule,
→ Fleming’s rule, → Hund’s rule,
→ left-hand rule, → Maxwell’s rule,
→ right-hand rule, → rigorous selection rule,
→ selection rule, and
→ Trouton’s rule.
A strip of rigid material marked off in units used especially for measuring length.
In some → planispheric astrolabes,
a bar which rotates across the front of the astrolabe and is used to locate
positions on the → rete,
and to relate them to the scale of hours
marked on the → limb. Also called the
→ index.
Etymology (EN): M.E. riule, reule, from
O.Fr. riule, from L. regula “straight stick, bar, ruler,”
related to regere “to rule, straighten, guide;” cognate with Pers. râst
“right, straight,” razan “rule,” as below. Etymology (PE): Razan from Av. razan “rule, order,” from
rāz- “to direct, put in line, set,” rasman-
“the lines or files of the army;”
O.Pers. rāsta- “straight, true,” rās- “to be right, straight,
true;”
Mid.Pers. râst “true, straight, direct;” Soghdian rəšt “right,”
rây-, râyênitan “to arrange;”
Mod.Pers. râst “right, true; just, upright, straight;”
raj “line, row,” variants raž, rak, râk, rezg (Lori),
radé, râdé “line, rule, row,”
rasté, râsté “row, a market with regular ranges of shops;”
ris, risé “straight;”
cf. Skt. raj- “to direct, stretch,” rjuyant- “walking straight;”
Gk. orektos “stretched out;”
L. regere “to lead straight, guide, rule,” p.p. rectus “right, straight;”
PIE base *reg- “move in a straight line,” hence, “to direct, rule.” |
