1. To expel saliva or phlegm from one's mouth into something. This medication makes my mouth water uncontrollably, so I have to keep spitting in a cup. The man spat in my eye as I walked past.

2. To eject or expel an object from one's mouth into something. In this usage, a noun or pronoun is used between "spit" and "in." If you're going to spit your gum in one of the coffee cups, please don't just leave it there for someone else to clean up! He kept chewing sunflower seeds and spitting their shells in a plastic cup during the lecture.