'Sternly' definitions:

Definition of 'sternly'

(from WordNet)
adverb
With sternness; in a severe manner; "`No,' she said sternly"; "peered severely over her glasses" [syn: sternly, severely]

Definition of 'Sternly'

From: GCIDE
  • Sternly \Stern"ly\, adv. In a stern manner. [1913 Webster]