"We will meet, but we will miss him,
There will be one vacant chair...."

an emptiness, a vacancy...but surely not 'nothingness'...we humans are able to give meaning to nothingness by means of language...a song being a special case. We all know that the 'nothing' in that chair where a friend should be is much more than just empty space...

we can joke..(and it is fun to play with the words)..but those two lines above make the point pretty well that we are almost never speaking of 'pure' nothing.