grievously

From Middle English grevously; equivalent to grievous +‎ -ly.

grievously (comparative more grievously, superlative most grievously)

1. In a grievous manner, severely.
   • c. 1587–1588, [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], part 1, 2nd edition, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire; London: Scolar Press, 1973, →ISBN, Act III, scene iii:

     Thoſe Chriſtian Captiues, which you keepe as ſlaues, […]
     when they chance to reſt or breath a ſpace,
     Are puniſht with Baſtones so grieuouſly,
     That they lie panting on the Gallies ſide.

   • 2011 November 21, David Gergen, “Have they gone nuts in Washington?”, in CNN.com‎:

     That's why this failure of the super committee represents a reckless, irresponsible gamble by our "leaders" in Washington. It's difficult to remember a Congress that has put the nation so much at risk in the service of ideology and to hold onto office. Partisans on both sides are grievously failing the country.