1752, past-participle adjective from verb convolute (1690s), from Latin convolutus, past participle of convolvere "to roll together," from assimilated form of com "with, together" (see con-) + volvere "to roll," from PIE root *wel- (3) "to turn, revolve." Or perhaps a back-formation from convolution. French has convoluté (18c.), in form a past-participle adjective, but without the verb.
convoluted reasoning
convoluted legal language
convivial
convocate
convocation
convoke
convolute
convoluted
convolution
convolve
convoy
convulse
convulsion