plaguily

from WordNet (r) 3.0 (2006)

plaguily
    adv 1: in a disagreeable manner; "it's so plaguey cold!" [syn:
           {plaguey}, {plaguy}, {plaguily}]

from The Collaborative International Dictionary of English v.0.48

Plaguily \Pla"gui*ly\, adv.
   In a plaguing manner; vexatiously; extremely. [Colloq.]
   "Ronsard is so plaguily stiff and stately." --Landor.
   [1913 Webster]