What is this?

[Marizna]

It’s taller than me

 

[RosemaryDW]

It looks like a wild lettuce to me but the leaves aren’t quite right. Maybe a variant from the one we have here.

Wild lettuce is a chicory: safe. But let’s see what others think.

 

[RosemaryDW]

ETA it really looks like a wild lettuce to me!

 

[Bambam1989]

I agree that it is some kind of wild lettuce. Some varieties can get to be over 12ft tall!