To envelop or enclose in a surrounding medium, as flames, water, etc. Frequently in passive. (Cf. 6d.) Also reflexive.

Of qualities, etc.: to invest, environ, or beset (a person, etc.); to encompass in some condition. Also with up. (Cf. 4.)

figurative. To envelop within the folds of some condition or circumstance; to environ, esp. so as to obscure or embarrass; to beset with difficulty…

said of mental influences.