Sentence:  Yet if he were <WSD>not</WSD> there , they would have missed him , as they would have missed the sounds of bees buzzing against the screen door in early June ; or the smell of thick tomato paste - the ripe smell that was both sweet and sour - rising up from aluminum trays wrapped in fly dotted cheesecloth . 
Meaning of the word marked with <WSD> tags:  negation of a word or group of words