Apart from our palms and the soles of our feet, all human skin is covered with hair.
What is the word for the fine hair on a human being’s skin?
I would be especially interested in what you would call it on the shoulder of an adolescent girl — that is, skin that we normally perceive as “hairless” —, in non-medical terms.
“Vellus hair” is of course the correct answer, but it seems to me that the average person would not know what that term means. “Peach fuzz”, on the other hand, seems to apply mostly to the face; that is, it denotes longer vellus hair in a place that has terminal hair in most men and many women. “Down” also seems to denote longer hair, both vellus and very soft and light terminal.
At this point it seems to me that there is no word for this kind of hair, probably because mostly we are unaware of it, and that you would have to describe it, possibly as “(very) fine hair”.
Sorry for the low image quality. Googling for an image of this is surprisingly hard. (But please don’t replace this image with one showing a different body part.)