1.
If you describe someone as ~, you are being critical of them because they are very determined to do what they want, and refuse to change their mind or be persuaded to do something else.
He is ~ and determined and will not give up...
= stubborn
ADJ disapproval
~ly
I stayed ~ly in my room, sitting by the telephone...
= stubbornly
ADV: ADV with v
obstinacy
I might have become a dangerous man with all that stubbornness and obstinacy built into me.
= stubbornness
N-UNCOUNT
2.
You can describe things as ~ when they are difficult to move, change, or destroy.
...rusted farm equipment strewn among the ~ weeds.
ADJ
~ly
...the door of the shop which ~ly stayed closed when he tried to push it open.
ADV: ADV with v