Definition of "Indiaman"

No place is so propitious to the formation either of close friendships or of deadly enmities as an Indiaman

1841, Thomas Babington Macaulay, Warren Hastings

Buried treasures are naturally among the problems which have come to Mr. [Sherlock] Holmes. One genuine case was accompanied by a diagram here reproduced. [...] Each Indiaman in those days had its own semaphore code, and it is conjectured that the three marks upon the left are signals from a three-armed semaphore.

1924 September, Arthur Conan Doyle, “Sidelights on Sherlock Holmes”, in Memories and Adventures, Boston, Mass.: Little, Brown, and Company, page 110