Old English mægen (Mercian megen) "power, bodily strength; force, violent effort; strength of mind or will; efficacy; supernatural power," from Proto-Germanic *maginam "power" (source also of Old High German megin "strength, power, ability"), suffixed form of PIE root *magh- "to be able, have power."

Original sense of "power" is preserved in phrase might and main. Also used in Middle English for "royal power or authority" (c. 1400), "military strength" (c. 1300), "application of force" (c. 1300). Meaning "chief or main part" (c. 1600) now is archaic or obsolete. Meaning "principal duct, pipe, or channel in a utility system" is first recorded 1727 in main drain.

Used since 1540s for "continuous stretch of land or water;" in nautical jargon used loosely for "the ocean," but in Spanish Main the word is short for mainland and refers to the coast between Panama and Orinoco (as contrasted to the islands of the West Indies).

"to give power or authority to," 1650s, also impower, from assimilated form of en- (1) + power (n.). Used by Milton, Beaumont, Pope, Jefferson, Macaulay, but the modern popularity dates from 1986. Related: Empowered; empowering.

"having the power to correct," 1530s, from French correctif, from Latin correct-, past-participle stem of corrigere "to put straight; to reform" (see correct (v.)). As a noun, "that which has the power of correction," from 1610s.

"power, inherent strength, ability to accomplish or effect," mid-15c., potencie, from Latin potentia "power," from potentem "potent," from potis "powerful, able, capable," from PIE root *poti- "powerful; lord." 

Old English heorcnung "a harkening, listening; power of hearing" (see hearken).

"flat wooden blade" used as a tool by potters, etc., for shaping their wares, early 15c., from Old French palete, diminutive of pale "spade, shovel" (see palette, which is the more French spelling of the same word). The original sense in English was medical, "flat instrument for depressing the tongue." Meaning "large portable tray" used with a forklift for moving loads is from 1921.

Latin, literally "beyond powers," from ultra "beyond" (see ultra-) + vires "strength, force, vigor, power," plural of vis (see vim). Usually "beyond the legal or constitutional power of a court, etc."

"generator for converting mechanical rotation into electric power," 1882, short for dynamo-machine, from German dynamoelektrischemaschine "dynamo-electric machine," coined 1867 by its inventor, German electrical engineer Werner Siemans (1816-1892), from Greek dynamis "power," from dynasthai "to be able, to have power, be strong enough," which is of unknown origin.

masc. proper name, from Old English Osweald "god-power, god-ruler," from Old English os "god" (only in personal names), from PIE *ansu- "spirit" (see Oscar) + Old English (ge)weald "power."

1670s, from Latin quintus "the fifth" (from PIE root *penkwe- "five") + ending from million. Compare billion. In Great Britain, the fifth power of a million (1 followed by 30 zeroes); in U.S. the sixth power of a thousand (1 followed by 18 zeroes).