guts
1. The stomach and/or intestines. If everything you eat makes you nauseous, there must be something going on with your guts.
2. The innards of something. First, we need to clean the guts out of the pumpkin, then we can carve it.
3. The internal components of something, usually something mechanical. We'll have to take the computer apart if there's a problem with its guts.
4. Courage, conviction, or resolve. Wow, you've got a lot of guts if mountain climbing is your hobby! I don't have the guts to ask my crush to the prom. You're always talking about quitting your job, but I don't think you have the guts to do it.