Rigdum Funnidos is a character in Henry Carey's Chrononhotonthologos (1734). Rigdum Funnidos is the comically plain-spoken contrast to the bombastic Aldiborontiphoscophornio. Both are courtiers, but whereas Aldiborontiphoscophornio might explain, when asked who Somnus is,
Rigdum Funnidos responds,
"This Gentleman may come of a very good Family, for aught I know; but I would not be in his Place for all the World." (I i, 47-54).Rigdum is both a Sancho Panza to the absurd Aldiborontiphoscophornio and a figure of the "Plain Dealer" (see The Plain Dealer by William Wycherly).
It is also Sir Walter Scott's nickname for John Ballantyne. Scott's epithet was a compliment. Conversely Aldiborontiphoscophornio was Scott's name for James Ballantyne in allusion to his pompous manner.
References
Rigdum Funnidos Wikipedia(Text) CC BY-SA