Send for boy serving knight (4)
I believe the answer is:
page
This might be a double definition.
'send for' is the first definition.
(I know that page is a type of summon)
'boy serving knight' is the second definition.
I know that 'boy' relates to this answer.
Can you help me to learn more?
(Other definitions for page that I've seen before include "lad wanted to run errands" , "contact" , "contribution to book?" , "Section of biography perhaps" , "Court attendant" .)