Castle suitable for jerks? (4,3)
I believe the answer is:
keep fit
'jerks?' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'castle suitable' is the wordplay.
'castle' becomes 'keep' (keep is a type of castle).
'suitable' becomes 'fit' (similar in meaning).
'keep'+'fit'='KEEP-FIT'
'for' is the link.
Can you help me to learn more?
(Other definitions for keep fit that I've seen before include "Exercise designed for physical wellbeing" , "Maintain health" , "Callisthenics" , "sort of exercise" , "Do physical exercises?" .)