Particle, See と・4, casual quoting particle
1. you said, he said, she said, they said
See たって・1, as たって; indicates supposition
2. if ... then
as かって; indicates a satirical or rhetorical question
3. do you seriously think that
indicates certainty, insistence, emphasis, etc.
4. I already told you, you should know by now that, of course
abbr. of という
5. the said ...