Antonyms of adj trivial

3 senses of trivial

Sense 1
fiddling, footling, lilliputian, little, niggling, piddling, piffling, petty, picayune, trivial -- ((informal) small and of little importance; "a fiddling sum of money"; "a footling gesture"; "our worries are lilliputian compared with those of countries that are at war"; "a little (or small) matter"; "a dispute over niggling details"; "limited to petty enterprises"; "piffling efforts"; "giving a police officer a free meal may be against the law, but it seems to be a picayune infraction")

INDIRECT (VIA unimportant) -> important, of import -- (of great significance or value; "important people"; "the important questions of the day")

Sense 2
superficial, trivial -- (of little substance or significance; "a few superficial editorial changes"; "only trivial objections")

INDIRECT (VIA insignificant) -> significant, important -- (important in effect or meaning; "a significant change in tax laws"; "a significant change in the Constitution"; "a significant contribution"; "significant details"; "statistically significant")

Sense 3
trivial -- (concerned with trivialities; "a trivial young woman"; "a trivial mind")

INDIRECT (VIA frivolous) -> serious -- (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!")

Similarity of adj trivial

3 senses of trivial

Sense 1
fiddling, footling, lilliputian, little, niggling, piddling, piffling, petty, picayune, trivial -- ((informal) small and of little importance; "a fiddling sum of money"; "a footling gesture"; "our worries are lilliputian compared with those of countries that are at war"; "a little (or small) matter"; "a dispute over niggling details"; "limited to petty enterprises"; "piffling efforts"; "giving a police officer a free meal may be against the law, but it seems to be a picayune infraction")
       => unimportant (vs. important) -- (not important; "a relatively unimportant feature of the system"; "the question seems unimportant")

Sense 2
superficial, trivial -- (of little substance or significance; "a few superficial editorial changes"; "only trivial objections")
       => insignificant (vs. significant), unimportant -- (devoid of importance, meaning, or force)

Sense 3
trivial -- (concerned with trivialities; "a trivial young woman"; "a trivial mind")
       => frivolous (vs. serious) -- (not serious in content or attitude or behavior; "a frivolous novel"; "a frivolous remark"; "a frivolous young woman")