I was reading the most common freerolling situations in holdem, but I have no idea what is being asked. What is Freerolling?
Google wasn't any help (hit too many free rolls vs. freerolling), and we didn't have any answers here that I found.
It's a term used to describe a situation in which there is no more downside risk involved for one or more active participants, only upside positive outcomes can be realized. A "shot to nothing" is a similar expression.
In the example from the question you link to, both players currently have the best hand, an Ace-high straight, yet only one player also has a flush draw. That player is freerolling as he can't lose (no downside risk) but can still beat his opponent by improving to a flush (upside).
In the context of poker, a freeroll is an opportunity to play with no cost, yet there are still potential rewards. Hence, any similar situation could be thought of as a chance at freerolling.