堑 qiàn, [塹], moat around a city 东非大地堑 DōngFēidàdìqiàn, [東非大地塹], Great East African rift valley 吃一堑,长一智 chīyīqiàn,zhǎngyīzhì, [吃一塹,長一智], Fall into the moat and you'll be wiser next time (idiom); One only learns from o... 地堑 dìqiàn, [地塹], trench, rift valley 路堑 lùqiàn, [路塹], (civil engineering) cutting (for a railway or highway)