One of the features of the dual language heritage of English is that there are social differences in the Norman French/Anglo Saxon sources. jeremyp has already mentioned food names. The nobility (whose forbears arrived with William the Conqueror) consumed meat to which they gave names derived from words their parents had used: beef, pork, mutton. The animals were looked after by indigenous Anglo Saxons and were given the names their parents had used: cow, pig, sheep.
As it happens, "fenestration" is a word used by architects to describe the way in which windows are arranged on the elevations of buildings they are designing. "Defenestration" should mean removing windows.
"Defenestration" appears to be used in an imprecise manner when it relates to someone being thrown through a window, perhaps "exfenestration" would be more correct. It may be that originally, when the act happened in a city far,far away (Prague) the term was meant to imply mordant humour on the part of the original writer.
So, the common people use the Norse word windows to identify the holes in buildings which let light through and the designers use the Latinate fenestration to identify their creative input.