[ˈsɪərɪəs], (Adjective)

Definitions:
- demanding or characterized by careful consideration or application
(e.g: marriage is a serious matter)

- acting or speaking sincerely and in earnest, rather than in a joking or half-hearted manner
(e.g: actors who are serious about their work)

- significant or worrying because of possible danger or risk; not slight or negligible
(e.g: she escaped serious injury)

- substantial in terms of size, number, or quality
(e.g: he suddenly had serious money to spend)


Phrases:

Origin:
late Middle English: from Old French serieux or late Latin seriosus, from Latin serius ‘earnest, serious’