The courts imprisoning one hundred and fifty? That's dramatic (10)
I believe the answer is:
theatrical
'dramatic' is the definition.
(thesaurus)
'the courts imprisoning one hundred and fifty?' is the wordplay.
'courts' becomes 'atria' (atrium is a kind of court).
'imprisoning' means one lot of letters goes inside another.
'one hundred' becomes 'c' (Roman numeral).
'and' means one lot of letters go next to another.
'fifty?' becomes 'l' (roman numeral).
'atria' enclosing 'c' is 'atrica'.
'the'+'atrica'+'l'='THEATRICAL'
'that's' is the link.
(Other definitions for theatrical that I've seen before include "Stagy" , "Artificial and exaggerated" , "Relating to acting/actors" , "affected" , "overdramatic" .)