envelop vs cocoon

envelop is not a noun while cocoon is a noun.

Word	Noun	Adjective	Verb	Adverb
envelop	No	No	Yes	No
cocoon	Yes	No	Yes	No

As verbs, cocoon is a hyponym of envelop; that is, cocoon is a word with a more specific, narrower meaning than envelop:

Other hyponyms of envelop include benight, tube, capsulate, capsule, capsulise, capsulize, engulf, sheathe, bathe, cover, enshroud, hide, shroud.

envelop (noun)	cocoon (noun)
	silky envelope spun by the larvae of many insects to protect pupas and by spiders to protect eggs

envelop (verb)	cocoon (verb)
enclose or enfold completely with or as if with a covering	wrap in or as if in a cocoon, as for protection
	retreat as if into a cocoon, as from an unfriendly environment