Answer:

oscillate

Answer	Crossword Clue
OSCILLATE	Behave like some fans
OSCILLATE	Swing both ways
OSCILLATE	Seesaw

OSCILLATE	Swing.
OSCILLATE	Waver
OSCILLATE	Swing
OSCILLATE	Swing to and fro

Crossword

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