The adjective, of course, is adminicular 'auxiliary, corroborative', which I intend to use whenever maximum obfuscation is a desideratum.    From Wordnik.com.  [languagehat.com: ADMINICLE.] Reference

He came: he found the islanders beside themselves at this unwelcome resurrection of the dead and the detested; he was shown, as adminicular of testimony, the traveller's uncouth and thick-soled boots; he argued, and finding argument unavailing, consented to enter the room and examine with his own eyes the sleeping Pict.    From Wordnik.com.  [Records of a Family of Engineers] Reference

He came: he found the islanders beside themselves at this unwelcome resurrection of the dead and the detested; he was shown, as adminicular of testimony, the traveller’s uncouth and thick-soled boots; he argued, and finding argument unavailing, consented to enter the room and examine with his own eyes the sleeping Pict.    From Wordnik.com.  [Records of a Family of Engineers] Reference