Word Study
backstair
CIDE DICTIONARY
backstair, a.
Private; indirect; secret; conducted with secrecy; intriguing; -- as if finding access by the back stairs; as, backstairs gossip. [1913 Webster]
"A backstairs influence." [1913 Webster]
"Female caprice and backstair influence." [1913 Webster]
For further exploring for "backstair" in Webster Dictionary Online