About the Guardian's row with royal attendant (8)
I believe the answer is:
courtier
'royal attendant' is the definition.
(I've seen this before)
'about the guardian's row' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'the guardian's' becomes 'our' (I've seen this in other clues).
'row' becomes 'tier' (tier is a kind of row).
'c'+'our'+'tier'='COURTIER'
'with' acts as a link.
(Other definitions for courtier that I've seen before include "Royal adviser" , "Attendant on monarch" , "Attendant at palace" , "Royal attendant" , "Messenger" .)