run down和run-down有何分別？

(1) run down有太多含義，擇其要者簡述如下：
意為tired and in poor health，指精疲力竭或身體衰弱，例如：

He has been working too hard and feels rather run down.

他工作太辛苦，感到精疲力竭。
(2) 又解作knock somebody to the ground, killing or injuring him，指撞倒在地、撞死或撞傷，例如：

He was run down by a cyclist.
他被一名騎腳踏車的人撞倒。
(3) 再解作cease to operate because of the exhaustion of motive，指（因動力耗盡而）停止運轉，例如：

Your clock has run down. The battery needs recharging.

你的鐘停了，電池需要充電。
(4) 還解作criticise unkindly或belittle，即不客氣地批評或貶低，例如：

He's always running his wife down in front of other people.

他總是在別人面前奚落自己的太太。
(5) run-down也有很多含義，只能簡述其中之一：

解作old and broken or in bad condition，指日久失修或破舊，例如：

This old run-down hotel will be demolished.
這間老舊破爛的酒店將被拆。