The Collaborative International Dictionary
Infestuous
Infestuous \In*fes"tu*ous\ (?; 135), a. [L. infestus. See
Infest, a.]
Mischievous; harmful; dangerous. [Obs.] ``Infestuous as
serpents.''
--Bacon.
Wiktionary
infestuous
a. (context obsolete English) mischievous; harmful; dangerous