Honest Einstein leaked information to mad scientist (12)
I believe the answer is:
frankenstein
'mad scientist' is the definition.
The definition suggests a singular noun which matches the answer.
'honest einstein leaked information' is the wordplay.
I cannot quite see how this works, but
'honest' could be 'frank' (similar in meaning) and 'frank' is found within the answer.
'information' could be 'i' (common abbreviation for information) and 'i' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for frankenstein that I've seen before include "Mary Shelley's monster-making baron" , "Animator" , "Mary Shelley novel" , "Monster's creator" , "Monstrous and dangerous humanoid" .)