Stupid prisoner starts to precipitate (8)
I believe the answer is:
condense
'precipitate' is the definition.
The answer and definition can be both related to change as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'stupid prisoner starts' is the wordplay.
'stupid' becomes 'dense' (similar in meaning).
'prisoner' becomes 'con' (abbreviation for 'convict').
'starts' says to put letters next to each other.
'dense' after 'con' is 'CONDENSE'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for condense that I've seen before include "Make more concentrated or compact" , "Compress or shrink" , "contract?" , "cut down" , "Abbreviate" .)