网友好，这里有个说法，您可以参考：

Webster's Third New International Dictionary, Unabridged

en·vel·op

transitive verb

also en·vel·ope \ə̇nˈveləp, en-\

(enveloped ; enveloped ; enveloping ; envelops also envelopes)

Etymology: Middle English envolupen, from Middle French envoluper, envoleper, enveloper, from Old French, from en- en- (I) + voluper, voleper, veloper to wrap up

1. 

 a. : to enclose completely with a garment or other covering : wrap up

  < a shroud enveloped her form — Mary W. Shelley >

  < drew off his coat and enveloped him in a white robe — Laura Krey >

  < other folks envelop the meat in the leaves — E.J.Banfield >

 b. : to enclose or surround with a nonsolid material or medium (as air or darkness) : obscure or conceal by covering or shrouding

  < distant hills enveloped in a blue haze >

  < large black clouds enveloped the moon >

  < flames enveloped the building >

  < a snug … warmth enveloped him — O.E.Rölvaag >

 c. : to surround or enfold with something immaterial (as a mood or atmosphere) : possess, dominate

  < the Presbyterian culture that enveloped me when I was a boy — St. Clair McKelway >

  < the drowsy silence that enveloped the yacht — Scott Fitzgerald >

  < she had been enveloped in profound peace — Ellen Glasgow >

  < then she would … envelop me in the great, soft, spicy tide of her affection — R.P.Warren >

  < a feeling of gloom and self-pity enveloped him >

  < he was enveloped by that strange sense of detachment — Walter O'Meara >

2. \“ or ˈenvəˌlōp or ˈänveˌlōp\ : to put in an envelope

 < she scrawled across the bottom of the letter the word NO and enveloped it for return mailing — E.P.O'Donnell >

3. : to attack or move to attack (one or both of an enemy's flanks)

 < there were indications that they intended to envelop the northern wing of Army Group South — W.R.Desobry >

Synonyms: see enclose

      如果这字典还算可以的话，envelop和envelope都对。