Answer:

impairs

Answer	Crossword Clue
IMPAIRS	Makes less effective
IMPAIRS	Spoils
IMPAIRS	Weakens

IMPAIRS	Damages.
IMPAIRS	Damages
IMPAIRS	Vitiates
IMPAIRS	Debilitates
IMPAIRS	Hampers

Crossword

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