Grave in manner or disposition; earnest; thoughtful; solemn; not light, gay, or volatile.
- Grave in quality or manner: gave me a serious look.
- Carried out in earnest: engaged in serious drinking; serious study of Italian.
- Deeply interested or involved: a serious card player.
- Designed for and addressing grave and earnest tastes: serious art; serious music.
- Not trifling or jesting: I'm serious: we expect you to complete the assignment on time. Her question was serious enough to deserve a thoughtful response.
- Informal Of considerable size or scope; substantial: a cleanup that cost serious money.
- Of such character or quality as to appeal to the expert, the connoisseur, or the sophisticate: "Every serious kitchen needs at least one peppermill” ( Washington Post).
- Concerned with important rather than trivial matters: a serious student of history.
- Being of such import as to cause anxiety: serious injuries; a serious turn of events.
- Too complex to be easily answered or solved: raised some serious objections to the proposal.