[1] : The Collaborative International Dictionary of English v.0.48

backstairs \back"stairs`\, backstair \back"stair`\, a.
   private; indirect; secret; conducted with secrecy;
   intriguing; -- as if finding access by the back stairs; as,
   backstairs gossip.

   syn: clandestine, cloak-and-dagger, hugger-mugger, hush-hush,
        on the quietpredicate, secret, subterranean,
        surreptitious, undercover, underground.
        1913 webster + wordnet 1.5

              a backstairs influence.             --burke.
        1913 webster

              female caprice and backstair influence.
                                                  --trevelyan.
        1913 webster

[2] : WordNet (r) 2.0

backstair
     adj : secret and sly or sordid; "backstairs gossip"; "his low
           backstairs cunning"- a.l.guerard; "backstairs
           intimacies"; "furtive behavior" syn: backstairs, furtive
see also:
backstairs furtive 

Backstair >> B Words
Backstair, definition of term: Backstair
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