Answer:

cause

Answer	Crossword Clue
CAUSE	Zealot's inspiration
CAUSE	Social movement
CAUSE	Something to believe in

CAUSE	Precipitate
CAUSE	Activist's passion
CAUSE	Thing to rally behind
CAUSE	Lead to
CAUSE	Reason
CAUSE	Bring about
CAUSE	Something to fight for
CAUSE	Effect preceder

CAUSE	Result in
CAUSE	Effect's partner
CAUSE	It may be lost or just
CAUSE	"Rebel Without a ..."
CAUSE	Effect, or effect's partner
CAUSE	Give rise to
CAUSE	Make happen
CAUSE	Grounds

CAUSE	Global warming, e.g.
CAUSE	Partner
CAUSE	Justification
CAUSE	Movement
CAUSE	Underlying reason
CAUSE	Saving the whales, e.g.
CAUSE	..-and-effect
CAUSE	.. celebre

CAUSE	Effect's mate
CAUSE	Principle
CAUSE	Crusade
CAUSE	Motivating issue
CAUSE	Demonstration impetus
CAUSE	Activist's concern
CAUSE	Bring on
CAUSE	Reason why

CAUSE	Trigger
CAUSE	Induce
CAUSE	Reply to "Why'd ya do that?"
CAUSE	Rallying point
CAUSE	Charitable undertaking

Crossword

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