Select the most appropriate ANTONYM of the given word.

Frivolous

Serious

The most appropriate antonym of the word frivolous is serious.

• Frivolous means "not having any serious purpose or value."
• Serious means "having or showing a sober or earnest attitude."

The other words do not have the same meaning as frivolous, so they are not its antonyms.

• Popular means "liked or enjoyed by many people."
• Reputed means "having a good reputation."
• Nervous means "easily upset or anxious."