关机
guān jī · HSK 2
to turn off
🔌 关 = close/shut + 机 = machine
关 means to close or shut (think 关门 close the door); 机 means machine or device. Together 关机 literally reads as shut-machine — power it off. Also used in film for wrapping a shoot.
关 — door 门 + simplified 关 inside
关 is the simplified form of 關. The traditional character showed a gate (門) with a bolt or crossbar inside, depicting a barred door — hence 'to close' or 'shut'. Meaning later extended to 'pass' (a guarded gate), 'barrier', and figuratively 'concern' or 'connection'.