Answer:

inexorable

Answer	Crossword Clue
INEXORABLE	Unyielding
INEXORABLE	Certain
INEXORABLE	Merciless

INEXORABLE	Relentless.
INEXORABLE	Unrelenting.
INEXORABLE	Set in stone

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.