Gigman, Carlyle's name for a man who prides himself on, and pays all respect to, respectability; derived from a definition once given in a court of justice by a witness who, having described a person as respectable, was asked by the judge in the case what he meant by the word; “one that keeps a gig,” was the answer.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Gifford, William * Gil Blas