1.
Something that is ~ continues to exist or happen for a long time; used especially about bad or undesirable states or situations.
His cough grew more ~ until it never stopped...
Shoppers picked their way through puddles caused by ~ rain.
ADJ
2.
Someone who is ~ continues trying to do something, even though it is difficult or other people are against it.
...a ~ critic of the government’s transport policies...
ADJ