The Collaborative International Dictionary of English v.0.48:

Scantly \Scant"ly\, adv.
   1. In a scant manner; not fully or sufficiently; narrowly;
      penuriously. --Dryden.
      [1913 Webster]

   2. Scarcely; hardly; barely.
      [1913 Webster]

            Scantly they durst their feeble eyes dispread
            Upon that town.                       --Fairfax.
      [1913 Webster]

            We hold a tourney here to-morrow morn,
            And there is scantly time for half the work.
                                                  --Tennyson.
      [1913 Webster]