This is the 10887th most frequent Turkish word.
devrilirken
"While tipping over" or "while falling over."
The word 'devrilirken' is used here as a conjunction implying a simultaneous action occurring while the chair (subject) is falling.
Rüzgar şiddetli esiyordu ve sandalye devrilirken ahşap zemine çarptı.
The wind was blowing strongly, and the chair hit the wooden floor as it was falling over.
The word 'devrilirken' indicates a temporal activity of the tree falling, during which the noise was perceived.
Ağaç devrilirken büyük bir gürültü duyuldu.
A loud noise was heard while the tree was falling.
Here, 'devrilirken' describes the ongoing action of tipping over that led to the cyclist losing balance.