* A single drop of rain rolled down the windowpane. (referring to a small amount of liquid)
* The doctor prescribed a few drops of medicine. (referring to a measured quantity of liquid)
* He took a drop of whiskey to settle his nerves. (referring to a small amount of alcohol)
* The temperature took a sudden drop. (referring to a decrease in something)
* There was a sharp drop in sales after the holiday. (referring to a sudden decrease in something)
* The climbers were exhausted after their long drop down the mountain. (referring to a descent)
* The parachute opened and he began his drop towards the ground. (referring to a descent)
* She had a drop of color in her cheeks. (referring to a hint of something)
* The band played a drop of a song before the main act. (referring to a short excerpt of a song)
As you can see, "drop" as a noun can have various meanings depending on the context.