Mind will wander with toy (8)
I believe the answer is:
windmill
'toy' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'mind will wander' is the wordplay.
'wander' indicates anagramming the letters.
'mind'+'will'='mindwill'
'mindwill' is an anagram of 'WINDMILL'.
'with' is the link.
Can you help me to learn more?
(Other definitions for windmill that I've seen before include "Building for grinding grain" , "Air-driven device" , "Natural energy generator" , "Source of green power" , "Wind generator" .)