Through the trainwindow, the rain continued to fall.
The Crossing-Place (1993)
He was smiling, looking out of the trainwindow at the spring sunshine.
Times, Sunday Times (2007)
Two people were hurt when cables smashed a trainwindow.
The Sun (2012)
Definition of 'window'
window
(wɪndoʊ)Explore 'window' in the dictionary
countable noun
A window is a space in the wall of a building or in the side of a vehicle, which has glass in it so that light can come in and you can see out.
Definition of 'train'
train
(treɪn)Explore 'train' in the dictionary
countable noun [oft byNOUN]
A train is a number of carriages, cars, or trucks which are all connected together and which are pulled by an engine along a railway. Trains carry people and goods from one place to another.