They are put to work by turns (12)
I believe the answer is:
screwdrivers
'turns' is the definition.
Although both the answer and definition are plural nouns, I can't understand how they can define each other.
'they are put to work' is the wordplay.
I cannot quite see how this works, but
'work' could be 'drive' (drive is a kind of work) and 'drive' is located in the answer.
This explanation may well be incorrect...
'by' acts as a link.
Can you help me to learn more?
(Another definition for screwdrivers that I've seen is " Household tools - orange juice and vodka drinks".)