What word can you use instead of the word something?

The noun that would take the place of the indefinite pronoun 'something' would depend on the context of the sentence; for example:

• You have something on your shirt. Or, You have a spot on your shirt. Or, You have mustard on your shirt.
• There is something wrong with my foot. Or, There is pain in my foot. Or, There is sticky stuff on my foot.
• I feel like doing something. Or, I feel like doing an activity. Or, I feel like going out. Or, I feel like a game.
• Something is missing. Or, A thing is missing. Or, An ingredient is missing. Or, A piece of furniture is missing. Or, A page is missing. Or, The door is missing. Or, A thousand dollars is missing. Or Whatis missing?