rack5

 
Pronunciation: /rak/

noun

verb

[no object, with adverbial of direction] archaic
  • (of a cloud) be driven before the wind: a thin shred of cloud racking across the moon

Origin:

Middle English (denoting a rush or collision): probably of Scandinavian origin; compare with Norwegian and Swedish dialect rak 'wreckage', from reka 'to drive'