(A). The second in a duel, as ?Name your friend,? ?Captain B. acted as his friend.?
?Mr. Baillie was to have acted as Disraeli's friend, if there had been a duel between that statesman and Daniel O'Connell.? ?Newspaper paragraph (December, 1885).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894