Other forms: purporting; purported; purports
Use purport when you want to convince people about something that might not be true, like when you purport that the dog ate your homework.
The verb purport can mean "to claim" — whether you mean it or not — or "to intend," like when you purport to study all night. So it makes sense that as a noun, purport means the intention or purpose, like the purport of a political candidate's speech was to get your vote. If the speech was long and hard to follow, you might be lucky just to get the purport, which here means "the main point or meaning."