1.
Something bad that is ~ never stops or never becomes less intense.
The pressure now was ~.
ADJ
~ly
The sun is beating down ~ly.
ADV
2.
Someone who is ~ is determined to do something and refuses to give up, even if what they are doing is unpleasant or cruel.
Relentless in his pursuit of quality, his technical ability was remarkable...
ADJ
~ly
She always questioned me ~ly.
ADV