HSK 7-9
机关
jīguān名形
mechanism; gear; machine-operated; office; agency; organ; organization; establishment; institution; body; stratagem; scheme; intrigue; plot; trick
古宅墙内藏有巧妙机关。
Gǔ zhái qiáng nèi cáng yǒu qiǎo miào jī guān.
An ingenious mechanism is hidden inside the old house wall.
Say it
Hold the button, say it, then let go.
Other HSK words sharing a character
Also free:
Appears across levels (7-9) in the HSK 3.0 word list.