Custodians of castle express hesitation for a second (7)
I believe the answer is:
keepers
'custodians' is the definition.
('keeper' can be a synonym of 'custodian')
'castle express hesitation for a second' is the wordplay.
'castle' becomes 'keep' (keep is a type of castle).
'express hesitation' becomes 'er' (sound made while hesitating - um, er. I am not sure about the 'express' bit.).
'for' is a charade indicator (letters next to each other).
'a second' becomes 's' (common abbreviation).
'keep'+'er'+'s'='KEEPERS'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for keepers that I've seen before include "Zoo attendants" , "Goalies" , "Players in goal" , "Custodians, stewards" .)