The way hands move is constant (6-3-5)
I believe the answer is:
around-the-clock
'constant' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'the way hands move' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'way' could be 'cl' (abbreviation for close as in road names) and 'cl' is present in the answer.
'hands' could be 'round' (round hand is a kind of hand) and 'round' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'is' acts as a link.
Can you help me to learn more?
(Another definition for around-the-clock that I've seen is " All day".)