Take part in show trial? (8)
I believe the answer is:
rehearse
'take' is the definition.
Although both the answer and definition are verbs in their base form, I don't see how one could define the other.
'part in show trial?' is the wordplay.
'part' becomes 're' (re is a kind of part).
'in show trial?' becomes 'hearse' (I am not sure about this - if you are sure you should believe this answer much more).
're'+'hearse'='REHEARSE'
Can you help me to learn more?
(Other definitions for rehearse that I've seen before include "Train" , "Practise before performing in public" , "prepare for performance" , "Run through (a play)" , "Practise before a public performance" .)