flour, powder, dust
粉 centers on finely ground or broken-down material: flour, powder, or dust. The common thread is a substance reduced to small, loose particles.
粉 combines 米 (rice) with 分 (divide/part), suggesting rice that has been divided or ground into fine particles.
Rice 米 is divided 分 into tiny pieces: that's flour or powder.
For フン, imagine a fun day of baking where you use flour: fun -> フン, and the flour is 粉.
flour; meal; powder; dust
pollen
wheat flour
fine powder
pulverization; pulverisation
in very small pieces
tooth powder; toothpaste
kinako; roasted soybean flour; roasted soy flour
embellishment (e.g. of a story); ornamentation; decoration
potato starch
starch
milk powder
shiruko; sweet red-bean soup with mochi
mineral dust; mine dust; fine particles; dust
breadcrumbs; panko
pollination
sparks
milling; grinding into flour
powder snow; powdery snow
gold dust