xuán yá
precipice
overhanging cliff
xuán yá lè mǎ
lit. to rein in the horse at the edge of the precipice (idiom); fig. to act in the nick of time
xuán yá qiào bì
sheer cliffs and precipitous rock faces (idiom)
xuán yá jué bì
sheer cliffs and precipitous rock faces (idiom)