Definition of "cypher"

Lady Bertram seems more of a cypher now than when he is at home; […]

1814 July, [Jane Austen], chapter XVII, in Mansfield Park: […], volume I, London: […] T[homas] Egerton, […], page 337

I have been critical of the RDG in the past for merely being a cypher for government announcements, but the failure of its members to make a stand on this issue and not be complicit in the Government's subterfuge is a shocking indictment of their failure to protect the industry.

2023 July 26, Christian Wolmar, “Closing ticket offices to lead to 'catch-22' for passengers”, in RAIL, number 988, page 42