This is the 13313th most frequent Turkish word.
kesilirken
"Kesilirken" means "while being cut" in English.
The word "kesilirken" here indicates the ongoing action of cutting the fabric.
Kumaş kesilirken dikkatli olmak gerekir.
You need to be careful while the fabric is being cut.
In this sentence, "kesilirken" suggests the time when the cutting of the tree is occurring.
Ağaç kesilirken etrafta kimse olmamalı.
No one should be around while the tree is being cut.
Here, "kesilirken" refers to the act of cutting the bread as the event during which crumbs fell.