Someone tried to 'slit' his throat. [=someone tried to kill him by cutting his throat]
She tried to 'slit her wrists'. [=to kill herself by cutting her wrists]
You could see through the 'slit' in the fence.
(..) You're Bellatrix Lestrange, not some school girl! Hey! Easy! If she gives us away, we must swear to use that sword to slit our own throats. Understand? No, he's right. I speak stupid. Okay. Let's do it. (..)2011 Harry Potter and the Deathly Hallows: Part 2