serious

Meaning

1. Without humor or expression of happiness; grave in manner or disposition
2. Important; weighty; not insignificant
3. Really intending what is said (or planned, etc); in earnest; not jocular or deceiving
4. Committed.

serious

grave

important

earnest

severe

solemn

heavy

critical

sober

stern

dangerous

grievous

strict

weighty

difficult

terrible

staid

alarming

violent

austere

grim

major

significant

dull

tense

sedate

profound

momentous

great

somber

sullen

hard

acute

strained

rigorous

big

deep

considerable

real

substantial

reliable

awful

diligent

honest

pressing

stringent

unplayful

large

unfunny

appreciable

key

sizable

gloomy

perilous

faithful

oppressed

massive

extreme

intense

tremendous

enormous

compelling

urgent

dreadful

unusual

cruel

very bad

crucial

taut

strenuous

practical

thoughtful

wise

life-threatening

good

high

no-nonsense

bad

responsible

serious-minded

sensible

grand

sincere

formal

serious talk

powerful

strong

tough

sure

gross

radical

heinous

conscientious

really

adult

full-grown

grown-up

of age

meaningful

glum

not light

heart-to-heart

sad

stormy

threatening

cordial

kind

warm

excessive

very great

classical

genuine

orthodox

extraordinary

incomparable

out of the ordinary

uncommon

dignified

exceedingly

frequently

sincerely

greater degree

risky

insignificant

noteworthy

vital

fatal

nervous

stiff

capital

tight

mortal

frowning

morose

sulky

unsmiling

extensive

dour

calm

serene

tranquil

nonsense

free from intoxication

brown

devout

shrewd

not trifling

provocative

authoritative

primary

principal

sensate

observable

perceivable

perceptible

tangible

burning

demure

matronal

matronly

saturnine

frabjous

of note

rigid

robust

stong

heartfelt

unadulterated

unfeigned

wholehearted

truly

mighty

turbulent

distressing

troublesome

testing

stable

complicated

pertinent

relevant

sobersided

unhumorous

Byzantine

arduous

awkward

bitter

challenging

sesquipedalian

troublous

unfriendly

unpronounceable

unutterable

sombre

humorless

leaden

oppressive

truthful

gigantic

huge

immense

vast

pointed

sharp

onerous

material

useful

coarse

obscene

more serious

trying

tragic

miserable

wretched

dire

ponderous

formidable

seriously

true

you don’t say

heavy responsibility

awesome

ferocious

worse

absolute

complete

patient

honored

unmoved

become heavy

trouble

weight

Frequency

Pronounced as (IPA)

/ˈsɪə.ɹi.əs/

From Middle English seryows, from Old French serieux, from Medieval Latin sēriōsus, an extension of Latin sērius (“grave, earnest, serious”), from Proto-Indo-European *swer- (“heavy”). Cognate with German schwer (“heavy, difficult, severe”), Old English swǣr (“heavy, grave, grievous”). More at swear, sweer.