Antonyms of adj ridiculous

3 senses of ridiculous

Sense 1
pathetic, ridiculous, silly -- (inspiring scornful pity; "how silly an ardent and unsuccessful wooer can be especially if he is getting on in years"- Dashiell Hammett)

INDIRECT (VIA undignified) -> dignified -- (having or expressing dignity; especially formality or stateliness in bearing or appearance; "her dignified demeanor"; "the director of the school was a dignified white-haired gentleman")

Sense 2
absurd, cockeyed, derisory, idiotic, laughable, ludicrous, nonsensical, preposterous, ridiculous -- (incongruous;inviting ridicule; "the absurd excuse that the dog ate his homework"; "that's a cockeyed idea"; "ask a nonsensical question and get a nonsensical answer"; "a contribution so small as to be laughable"; "it is ludicrous to call a cottage a mansion"; "a preposterous attempt to turn back the pages of history"; "her conceited assumption of universal interest in her rather dull children was ridiculous")

INDIRECT (VIA foolish) -> wise -- (having or prompted by wisdom or discernment; "a wise leader"; "a wise and perceptive comment")

Sense 3
farcical, ludicrous, ridiculous -- (broadly or extravagantly humorous; resembling farce; "the wild farcical exuberance of a clown"; "ludicrous green hair")

INDIRECT (VIA humorous) -> humorless, humourless, unhumorous -- (lacking humor; "it was a humorless wink; a wink of warning"- Truman Capote)

Similarity of adj ridiculous

3 senses of ridiculous

Sense 1
pathetic, ridiculous, silly -- (inspiring scornful pity; "how silly an ardent and unsuccessful wooer can be especially if he is getting on in years"- Dashiell Hammett)
       => undignified (vs. dignified) -- (lacking dignity)

Sense 2
absurd, cockeyed, derisory, idiotic, laughable, ludicrous, nonsensical, preposterous, ridiculous -- (incongruous;inviting ridicule; "the absurd excuse that the dog ate his homework"; "that's a cockeyed idea"; "ask a nonsensical question and get a nonsensical answer"; "a contribution so small as to be laughable"; "it is ludicrous to call a cottage a mansion"; "a preposterous attempt to turn back the pages of history"; "her conceited assumption of universal interest in her rather dull children was ridiculous")
       => foolish (vs. wise) -- (devoid of good sense or judgment; "foolish remarks"; "a foolish decision")

Sense 3
farcical, ludicrous, ridiculous -- (broadly or extravagantly humorous; resembling farce; "the wild farcical exuberance of a clown"; "ludicrous green hair")
       => humorous (vs. humorless), humourous -- (full of or characterized by humor; "humorous stories"; "humorous cartoons"; "in a humorous vein")