起こす
おこす · okosu · JLPT N4 · verb-godan
to wake (someone) up
⏰ 起 = rise; 起こす makes someone rise, 起きる is rising yourself
起こす is the transitive partner of 起きる (to get up). The -su ending often marks doing the action to someone else, as in 落とす or 出す. Sound hook: oh-KO-su, as in Oh, COme on, SUnrise, get up!
起 — 走 (run) + 己 (self/phonetic)
起 combines 走 'run/walk' as the meaning component with 己 as the phonetic component. The 走 element suggests movement of the body, giving the core sense of rising up or starting to move. From there it extended to meanings like 'get up,' 'begin,' and 'arise.'