An Etymological Dictionary of Astronomy and Astrophysics

1. A bed for a baby that is usually designed to rock back and forth when pushed gently. → Newton’s cradle.
   

2. The place where something begins (Merriam-Webster.com).

Etymology (EN): M.E. cradel, from O.E cradol akin to O.H.G. kratto “basket,” Ger. Krätze “basket carried on the back;” Pers. gereh “knot;” Skt. granth- “to tie a knot” (Cheung 2007).

Etymology (PE): Gahvâré “cradle,” variants gâhvâré, gowvâré, govâré, from Mid.Pers. gâhwârag “cot, cradle.”