Skip to the word

Added 9 October 2026

serious

/ˈsɪə̯.ɹi.əs/ adjective

In Latin: sērius Wiktionary

adjective Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about serious at Wordnik → Where our words come from →

Concerned with work or important matters rather than play or trivialities.
a serious student of history
Of great consequence.
marriage is a serious matter
Causing fear or anxiety by threatening great harm.
a dangerous operation

Origin

From Middle English seryows, from Old French serieux, from Medieval Latin sēriōsus, an extension of Latin sērius (“grave, earnest, serious”), possibly ultimately from Proto-Indo-European *swer- (“heavy”). (If this root is correct, cognate with German schwer (“heavy, difficult, severe”), Old English swǣr (“heavy, grave, grievous”). More at swear, sweer. However, see sērius for an alternative derivation of the Latin.)

From Wiktionary, via Kaikki.org (CC BY-SA)

Back to today's word