Enduringly

1 clue
In a permanent way
Similar answers:
Achingly
Adoringly
Amazingly
Appealingly
Bitingly
Boastingly
Caressingly
Condescendingly
Cunningly
Cuttingly
Daringly
Dashingly
Disarmingly
Disconcertingly
Endurable
Endurance
Endurancetest
Endurancetests
Endure
Endured