To hit hard, experienced hands move like this (9)
I believe the answer is:
clockwise
'hands move like this' is the definition.
(hands move clockwise round a clock)
'to hit hard experienced' is the wordplay.
'to hit hard' becomes 'clock' (clock can informally mean to smack).
'experienced' becomes 'wise'.
'clock'+'wise'='CLOCKWISE'
(Other definitions for clockwise that I've seen before include "Moving as hands do?" , "going round as usual?" , "Direction of movement on dial" , "In a circular direction" , "Cow sickle (anag.)" .)