Purposeful and unwavering (8)
I believe the answer is:
resolute
'purposeful and unwavering' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for resolute that I've seen before include "Determined, firm" , "Purposeful and unwavering" , "Determined or decided" , "in a determined manner" , "'With fixed purpose, steadfast (8)'" .)