I couldn't resist looking it up as it sounded a bit saucier than it actually is.

To Pronate (verb) means either: -

1. Turn hand palm down. transitive verb to turn the hand or forearm so that the palm faces downwards

or,

2. rotate foot inwards. transitive and intransitive verb to rotate the bones of the foot so that the weight is borne mainly on the inside of the foot.

Hope this helps.

Cheers.
Lee.