Which word?
Window, or licker?
Trying to look at is from a reflection of modern day popular slang, as well as from a socio-economic context, I conclude that it is in fact TWO words.
In the context of my work - providing window cleaning services with a chamois leather and a leaky bucket - the answer is obviously YES.
Depends on the context it is used. The word Tart can be offensive if used in some contexts.