Synonyms for Seriously:

adv

badly (adverb)
gravely.
hard (adverb)
actively.

adv.

dangerously, critically (adverb)
severely, very, badly.
extremely (adverb)
very.
not humorously (adverb)
earnestly, in earnest, sedately, sincerely, solemnly, actively, gravely.
soberly (adverb)
sedately.
truthfully (adverb)
sincerely.

n.

e'en, actively, e'er, any, dangerously, actual, safely, entirely, even, bloody. injurious, damaging, perilous, disastrous, hazardous, dangerous, unsafe, risky, ruinous, harmful. well, very, indeed, a lot, thoroughly, deeply. deep, officious, solemn, serious, substantial, humorlessly, stolid, funereal, sober. seriously (noun)
earnestly, gravely, in earnest, badly, severely.

Other synonyms:

dangerously, solemnly.

Usage examples for seriously

  1. " I'm obliged to you, sir," he said seriously – The Tempering by Charles Neville Buck
  2. I know the papers tried to make something out of it but I find it hard to believe that you took it seriously – The Last Straw by William J. Smith
  3. Certainly I never saw so pretty a girl as this one, I hope she is not seriously hurt. – The Red Cross Girls with Pershing to Victory by Margaret Vandercook