Loyal and steadfast (8)
I believe the answer is:
faithful
'loyal and steadfast' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for faithful that I've seen before include "Constant and true" , "Steadfast and true" , "Loyal and true" , "Steadfast in affection or allegiance" , "Loyal and steadfast" .)