一騎当千[ikkitousen] being a match for a thousand
一刻千金[ikkokusenkin] every moment is precious
一字千金[ichijisenkin] word of great value
一千[issen] 1,000
一望千里[ichibousenri] sweeping view of the eye

一瀉千里[isshasenri] one swift effort
引き千切る[hikichigiru] to tear off
何千[nanzen] many thousands
海千山千[umisenyamasen] sly old dog
幾千[ikusen] thousands

一念発起[ichinenhokki] being resolved to (do something)
引き起す[hikiokosu] to cause
縁起[engi] omen
喚起[kanki] arousal
起きる[okiru] to get up

起上る[okiagaru] to rise
起す[okosu] to raise
起こり得る[okoriuru] to be possible to occur
起る[okoru] to occur
起つ[tatsu] to rise up