Indefatigable (10)
'indefatigable' is the definition.
(I know that indefatigable can be written as tireless)
This is all the clue.
(Other definitions for tireless that I've seen before include "Full of energy" , "Never wearying" , "Having great energy" , "Indefatigable, unflagging" , "Full of stamina" .)
'indefatigable' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for persistent that I've seen before include "Tenacious; constant" , "Resolute - interminable" , "Not taking "no" for an answer" , "hanging on" , "not giving up" .)