Source: cirosantilli/partial-derivative-symbol
= Partial derivative symbol
{tag=Mathematical symbol that looks like a Greek letter but isn't}
{title2=$\partial$}
Nope, it is not a <Greek letter>, notably it is not a lowercase <delta>. It is just some random made up symbol that looks like a <letter D>. Which is of course derived from <delta>, which is why it is all so damn confusing.
I think the symbol is usually just read as "<D>" as in "d f d x" for $\pdv{F(x, y, z)}{x}$.