adj
serious
SEER-ree-uhs
adj
1
Not joking or humorous; solemn in manner.
"He gave her a serious look and said nothing more."
"She kept a serious expression during the entire meeting."
2
Important, significant, or potentially harmful.
"The doctors said his condition was serious but stable."
3
Genuinely meaning what one says, not joking around.
"Are you serious about quitting your job?"
How to Use Serious
Learner’s notesIn plain EnglishGrave or earnest — either in someone's manner, or describing something important or dangerous.
Common pairings
serious problem
dead serious
serious injury
Word Forms
more serious comparative, most serious superlative
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He gave her a _____ look and said nothing more.
Etymology
From Old French serieux, from Medieval Latin sēriōsus, based on Latin sērius, "grave, earnest."