■ adjective
1》 demanding or characterized by careful consideration or application.
↘solemn or thoughtful.
2》 sincere and in earnest, rather than joking or half-hearted.
3》 significant or worrying in terms of danger or risk: ~ injury.
4》 informal substantial in terms of size, number, or quality: ~ money.
Derivatives
~ness noun
Origin
ME: from OFr. serieux or late L. seriosus , from L. serius 'earnest, ~'.