乱す
みだす · midasu · JLPT N1 · verb-godan
to disturb
乱 (chaos, disorder) + す (to make/do): to make things into chaos, i.e. to disarrange
The 乱 kanji is read 'ran' or 'mida' and means disorder or rebellion. Adding す (to do) gives 'to make into disorder', so 乱す is the verb: disturb, throw into disarray.
乱 — hand 又 + tangled silk 𠬪/乿 component
乱 is the simplified form of 亂. The traditional character depicts hands above and below untangling silk threads on a frame, with 乙 on the right. It originally meant 'to put tangled threads in order,' but came to mean both 'disorder' and 'to govern chaos.'