Mean criminal act with one displacing article (10)
I believe the answer is:
constitute
'mean' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
'criminal act with one displacing article' is the wordplay.
I cannot really see how this works, but
'criminal' could be 'con' (abbreviation for 'convict') and 'con' is found within the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for constitute that I've seen before include "Be (a part) of a whole" , "Found" , "form" , "Make up" .)