Loyalty shown by chap caught in hold (10)
I believe the answer is:
allegiance
'loyalty' is the definition.
(allegiance is a kind of loyalty)
'chap caught in hold' is the wordplay.
'chap' becomes 'ianc' (I can't justify this - if you can you should believe this answer much more).
'caught in' means one lot of letters goes inside another.
'hold' becomes 'allege' (both can mean to claim or maintain).
'ianc' going within 'allege' is 'ALLEGIANCE'.
'shown by' is the link.
Can you help me to learn more?
(Other definitions for allegiance that I've seen before include "Loyalty (to a superior)" , "commitment to a cause" , "Fidelity" , "duty" , "Loyalty to a group or cause" .)