The Collaborative International Dictionary of English v.0.48:

Middling \Mid"dling\, a.
   Of middle rank, state, size, or quality; about equally
   distant from the extremes; medium; moderate; mediocre;
   ordinary. "A town of but middling size." --Hallam.
   [1913 Webster]

         Plainly furnished, as beseemed the middling
         circumstances of its inhabitants.        --Hawthorne.
   [1913 Webster] -- Mid"dling*ly, adv. -- Mid"dling*ness,
   n.
   [1913 Webster]