The Collaborative International Dictionary
Insidiate
Insidiate \In*sid"i*ate\, v. t. [L. insidiatus, p. p. of
insidiare to lie in ambush, fr. insidiae. See Insidious.]
To lie in ambush for. [Obs.]
--Heywood.
Wiktionary
insidiate
vb. (context obsolete English) To lie in ambush for.