Definition of "hansom"

I rose accordingly from table, got into a hansom, and drove straight to Jekyll's house.

1886, Robert Louis Stephenson, The Strange Case of Dr Jekyll and Mr Hyde

“There the cause of death was soon ascertained ; the victim of this daring outrage had been stabbed to death from ear to ear with a long, sharp instrument, in shape like an antique stiletto, which […] was subsequently found under the cushions of the hansom. […]”

1905, Baroness Emmuska Orczy, chapter 1, in The Tremarn Case‎

The ghost of Selby stirred in him. His thoughts slipped back to the day when he had stolen from his well-appointed office to a waiting hansom—there had still been a good many hansoms in those days—and driven quickly to the docks.

1931, Francis Beeding, “6/4”, in Death Walks in Eastrepps‎