This is the 2897th most frequent Dutch word.
achterover
"Achterover" means "backward" or "on one's back" in English.
Here, 'achterover' means backward, indicating the direction of the fall.
Hij viel achterover van de stoel.
He fell backward off the chair.
In this sentence, 'achterover' describes the direction of the leaning motion, which is towards the back.
Ze leunde achterover om de sterren te bekijken.
She leaned backwards to look at the stars.
'Achterover' is used figuratively to describe the action of metaphorical amazement or surprise as if falling backward.