An Etymological Dictionary of Astronomy and Astrophysics

1. Physics: The → rate of doing → work on transferring → energy, as expressed in ergs/sec, watts, etc. Same as → mechanical power.
   

2. Math.: An → exponent to which a given quantity is raised. The expression xⁿ is therefore known as “x to the n-th power.”

Etymology (EN): M.E. pouer(e), poer(e), from O.Fr. povoir, noun use of the infinitive in O.Fr., “to be able,” from V.L. *potere, from L. potis “powerful, able, capable;”
cognate with Av. paiti- “lord, husband;” Mod.Pers. -bad (sepah-bad “general, commander of an army”); Skt. pái-
“master, husband;” Gk. posis “husband;” Lith. patis “husband.”

Etymology (PE): Tavân “power, strength,” tavânestan “to be powerful, able;” Mid.Pers. tuwan “power, might,” from O.Pers./Av. base tav- “to have power, to be strong, to be able,” Av. tavah- “power,” təviši- “strength,” Mod.Pers. tuš, tâb “power, ability,” O.Pers. tauman- “power, strength,” tunuvant- “powerful,” Skt. tu- “to be strong, to have authority,” tavas-, tavisa- “strong, energetic,” tavisi- “power, strength.”