serious: [15] Serious comes ultimately from Latin sērius ‘serious, grave’. From this was derived late Latin sēriōsus, which passed into English via Old French serieux. It is not clear where sērius came from, although some have linked it with German schwer ‘heavy’ (‘seriousness’ and ‘weightiness’ being semantically close).
serious (adj.)
mid-15c., "expressing earnest purpose or thought" (of persons), from Middle French sérieux "grave, earnest" (14c.), from Late Latin seriosus, from Latin serius "weighty, important, grave," probably from a PIE root *swer- (4) "heavy" (cognates: Lithuanian sveriu "to weigh, lift," svarus "heavy;" Old English sw?re "heavy," German schwer "heavy," Gothic swers "honored, esteemed," literally "weighty"). As opposite of jesting, from 1712; as opposite of light (of music, theater, etc.), from 1762. Meaning "attended with danger" is from 1800.
例文
1. I know it 's nothing serious and I feel quite unemotional about it.
それは大したことではないことを知っているので、少し無関心です。
2.Smoking places you at serious risk of cardiovascular and respiratory disease.
喫煙は心臓血管や呼吸器疾患にかかるリスクを大きく高める。
3.She was fitted with a pacemaker after suffering serious heart trouble.
彼女は深刻な心臓病にかかった後、心臓ペースメーカーを設置した。
4.The allegations are serious enough to warrant an investigation.
これらの告発は深刻であり、調査が必要である。
5.He sustained serious neck injuries after he broke someone 's fall.