Antonyms of adj serious

6 senses of serious

Sense 1
serious (vs. frivolous) -- (concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!")

frivolous (vs. serious) -- (not serious in content or attitude or behavior; "a frivolous novel"; "a frivolous remark"; "a frivolous young woman")
        => airheaded, dizzy, empty-headed, featherbrained, giddy, light-headed, lightheaded, silly -- (lacking seriousness; given to frivolity; "a dizzy blonde"; "light-headed teenagers"; "silly giggles")
        => flighty, flyaway, head-in-the-clouds, scatterbrained -- (guided by whim and fancy; "flighty young girls")
        => flippant, light-minded -- (showing inappropriate levity)
        => idle, light -- (silly or trivial; "idle pleasure"; "light banter"; "light idle chatter")
        => light -- (intended primarily as entertainment; not serious or profound; "light verse"; "a light comedy")
        => trivial -- (concerned with trivialities; "a trivial young woman"; "a trivial mind")

Sense 2
serious -- (of great consequence; "marriage is a serious matter")

INDIRECT (VIA important) -> unimportant -- (not important; "a relatively unimportant feature of the system"; "the question seems unimportant")

Sense 3
dangerous, grave, grievous, serious, severe, life-threatening -- (causing fear or anxiety by threatening great harm; "a dangerous operation"; "a grave situation"; "a grave illness"; "grievous bodily harm"; "a serious wound"; "a serious turn of events"; "a severe case of pneumonia"; "a life-threatening disease")

INDIRECT (VIA critical) -> noncritical, noncrucial -- (not in a state of crisis or emergency)

Sense 4
good, serious -- (appealing to the mind; "good music"; "a serious book")

INDIRECT (VIA intellectual) -> nonintellectual -- (not intellectual)

Sense 5
unplayful (vs. playful), serious, sober -- (completely lacking in playfulness)


Sense 6
serious -- (requiring effort or concentration; complex and not easy to answer or solve; "raised serious objections to the proposal"; "the plan has a serious flaw")

INDIRECT (VIA difficult) -> easy -- (posing no difficulty; requiring little effort; "an easy job"; "an easy problem"; "an easy victory"; "the house is easy to heat"; "satisfied with easy answers"; "took the easy way out of his dilemma")

Similarity of adj serious

6 senses of serious

Sense 1
serious (vs. frivolous) -- (concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!")
       => earnest, sincere, solemn -- (characterized by a firm and humorless belief in the validity of your opinions; "both sides were deeply in earnest, even passionate"; "an entirely sincere and cruel tyrant"; "a film with a solemn social message")
       => grave, sedate, sober, solemn -- (dignified and somber in manner or character and committed to keeping promises; "a grave God-fearing man"; "a quiet sedate nature"; "as sober as a judge"; "a solemn promise"; "the judge was solemn as he pronounced sentence")
       => overserious -- (excessively serious)
       => real -- (not to be taken lightly; "statistics demonstrate that poverty and unemployment are very real problems"; "to the man sleeping regularly in doorways homelessness is real")
       => thoughtful, serious-minded -- (acting with or showing thought and good sense; "a sensible young man")
       => sobering -- (tending to make sober or more serious; "the news had a sobering effect")
       => solid -- (of a substantial character and not frivolous or superficial; "work of solid scholarship"; "based on solid facts")

Sense 2
serious -- (of great consequence; "marriage is a serious matter")
       => important (vs. unimportant), of import -- (of great significance or value; "important people"; "the important questions of the day")

Sense 3
dangerous, grave, grievous, serious, severe, life-threatening -- (causing fear or anxiety by threatening great harm; "a dangerous operation"; "a grave situation"; "a grave illness"; "grievous bodily harm"; "a serious wound"; "a serious turn of events"; "a severe case of pneumonia"; "a life-threatening disease")
       => critical (vs. noncritical) -- (being in or verging on a state of crisis or emergency; "a critical shortage of food"; "a critical illness"; "an illness at the critical stage")

Sense 4
good, serious -- (appealing to the mind; "good music"; "a serious book")
       => intellectual (vs. nonintellectual) -- (appealing to or using the intellect; "satire is an intellectual weapon"; "intellectual workers engaged in creative literary or artistic or scientific labor"; "has tremendous intellectual sympathy for oppressed people"; "coldly intellectual"; "sort of the intellectual type"; "intellectual literature")

Sense 5
unplayful (vs. playful), serious, sober -- (completely lacking in playfulness)

Sense 6
serious -- (requiring effort or concentration; complex and not easy to answer or solve; "raised serious objections to the proposal"; "the plan has a serious flaw")
       => difficult (vs. easy), hard -- (not easy; requiring great physical or mental effort to accomplish or comprehend or endure; "a difficult task"; "nesting places on the cliffs are difficult of access"; "difficult times"; "why is it so hard for you to keep a secret?")