What do the Ms in ml and ms quantum numbers stand for?

[Stickybees]

I first thought magnetic, but that only makes sense for ml, they're both projections though, does anyone know what they stand for?

Thanks!

 

[dauto]

m stands for magnetic
s stands for spin
l stands for ?

Keep in mind that these are just labels of at most historical significance.

 

[Stickybees]

I think it must just be 'momentum' from searching a bit more.