to lean out of the window

[Marina Gaidar]

Is it correct to say "to lean out of the window" meaning that somebody bends over the window frame to see better the street.

[Rover_KE]

Yes, it is.

Rover

[emsr2d2]

Is it correct to say "to lean out of the window" meaning that somebody bends over the window frame to see better the street.

At the end of your sentence, you need either "to better see the street" or "to see the street better" but not the word order you used.