Tenacious (6)
'tenacious' is the definition.
(I know that tenacious can be written as persistent)
This is all the clue.
(Other definitions for persistent that I've seen before include "Resolute - interminable" , "Tenacious; constant" , "Lasting, prolonged" , "Determined" , "Pressing" .)
'tenacious' is the definition.
(dogged can mean tenacious or determined)
This is the entire clue.
(Other definitions for dogged that I've seen before include "Resolute; trailed" , "Worried" , "Grimly persistent" , "Followed - stubborn" , "stubbornly persevering" .)