in a serious manner or to a serious degree extremely or remarkably: seriously tall
WordReference Random House Learner's Dictionary of American English © 2026
se•ri•ous•ly /ˈsɪriəsli/USA pronunciation
adv. to an extent that causes worry or fear:He was seriously ill.
in a way deserving careful thought:We have to take their threats seriously.
(used to express the feeling that what is said is important and should be listened to):When the laughter died down he continued, "But seriously, folks, we do have a major problem.''
WordReference Random House Unabridged Dictionary of American English © 2026- in a serious manner:studied seriously for the test.
se•ri•ous•ly
(sēr′ē əs lē),USA pronunciation adv.
- in a serious manner:He shook his head seriously.
- to an alarmingly grave extent:seriously ill.
- with genuine, earnest intent;
sincerely:Seriously, kids, we have to get home before dark.
- serious + -ly 1500–10
Collins Concise English Dictionary © HarperCollins Publishers::
'seriously' also found in these entries (note: many are not synonyms or translations):
Kharijite
- advice
- altogether
- anointing of the sick
- antimagnetic
- anybody
- armillaria root rot
- bad
- balance of power
- bird
- breeze
- business
- childcare
- criminal contempt
- critical
- death tourist
- deplete
- earnest
- economy
- extremely
- facetious
- flawed
- fun
- garden
- grave
- grudge
- heart
- humorous
- hyper
- indigence
- joke
- kibitzer
- long
- malice aforethought
- mercy flight
- od
- orthogenic
- pale western cutworm
- pensive
- peril point
- play
- pulverize
- read
- really
- skite
- sport
- sportive
- steam
- subjunctive
- take