paper
paperweight
flypaper
sandpaper
The words weight, fly and sand have "fly" in common, because together they can form other words. Their direct relationship is: fly, fly weight, and sand fly.
The words weight, fly, and sand are all nouns. The words can all be used as the subject in a sentence.
Paper is what weight, fly, and sand have in common. Paperweight, flypaper, and sandpaper is how paper is common for all of them.
paper as in ... paperweight flypaper sandpaper
The word is paper: paperweight fly paper sandpaper
weight fly sand
Fire
The word 'paper' will make each a compound word:paper weightfly papersand paper
flowers
a fly is not an element so it does not have an "atomic" weight. It does have a mass or weight however
It is the scientific term for a sand fly
London's sand it too coarse