stubborn

stub|born /st'ʌbə^rn/
1 [ADJ]
Someone who is stubborn or who behaves in a stubborn way is determined to do what they want and is very unwilling to change their mind.
He is a stubborn character used to getting his own way...
= obstinate
● stubbornly [ADV]
He stubbornly refused to tell her how he had come to be in such a state.
● stubbornness [N-UNCOUNT]
I couldn't tell if his refusal to talk was simple stubbornness.
2 [ADJ] usu ADJ n
A stubborn stain or problem is difficult to remove or to deal with.
This treatment removes the most stubborn stains...
= persistent
● stubbornly [ADV]
Some interest rates have remained stubbornly high.