Basically, a long way of saying that
something is true. Especially funny if you can get an adult, especially a teacher to say it because it makes them sound like they're trying to be
hip. Can also be used in question form (e.g.
2)
Example 1
Person 1) I've finished everything.
Person
2) Really?
Person 1) Straight up no word of a lie
Example
2
Person 1) I've finished everything.
Person
2) Straight up no word of a lie?
Person 1) Hell yeah!