Why Is The Milky Way Named The Milky Way?

Because that streak of densely packed stars looks like droplets of milk sprayed across the dark night time sky.  That's what the Greeks reckoned, and all of Western Europe has inherited their terms for describing what it looks like.

It's easy for us to forget that in ancient times most people's jobs were involved with food production. So everybody would have had some experience of seeing milk spilled on the ground, the cow's, a goat's, from sheep, dogs, cats or horses -- and definitely a mother's milk as it sometimes sprays from the breast after feeding a baby.

Read here more about the history of the names Milky Way and Galaxy.  Both these terms refer to milk.