What makes the material conditional material (also called the material implication)?
What does this logical connective have to do with matter?
Googling doesn't seem to help.
The term "material implication" was coined by Russell, who made a distinction between formal and material implication.
Here's a quote from the Principia:
[W]herever [...] one particular proposition is deduced from another, material implication is involved, though as a rule the material implication may be regarded as a particular instance of some formal implication, obtained by giving some constant value to the variable or variables involved in the said formal implication.
So material implication concerns implication between particular propositions, whereas formal implication is supposed to be more general. It doesn't have much to do with matter as in physical stuff, it is material only in the sense of being a particular instance of something.
Nowadays the term "material conditional" just means the familiar conditional with its familiar truth conditions. I don't think that "formal conditional" or "formal implication" is still used though, but maybe others could elaborate.
Also note that there are other conditionals which are not material, like the subjunctive conditional (e.g. "If Oswald had not shot Kennedy, then someone else would have").