Answer:

preclude

Answer	Crossword Clue
PRECLUDE	Make impossible
PRECLUDE	Rule out in advance
PRECLUDE	Shut out

PRECLUDE	Make impossible.
PRECLUDE	Shut out.
PRECLUDE	Prevent.
PRECLUDE	Head off
PRECLUDE	Prevent from happening

Crossword

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