In Gossip Girl Season 4 Episode 19 "Petty in pink," Blair says the following sentence to Serena's cousin Charlie after she tried to explain to both of them about her plan.
I'm only grandfathering you in because of Serena.
What this "grandfather" mean here? It looks like a verb, but I can't find it in any dictionary.
Piskvor offered the relevant link, which can tell you more about the history of the expression. "Grandfathering" means that an exception is made because something existed before the rules were changed. I don't know what the context is in the example you've given, but here's an example:
My company recently began requiring us to write our documentation in Google docs. My current project is grandfathered; I can still use the old file sharing system because that's what I used when I started documenting, before the change was made.
I hope that clears things up.
Oh, and I think "grandfathering you in" sounds odd. This doesn't strike me as a normal way to use the phrase.
A grandfather clause is a rule allowing currently running arrangements to continue despite new regulations.
In the most abstract sense, "grandfathered in" means that the subject is still functioning under an old rule after a rule change. This is related to "grandfather clause," which is the specific clause in a rule change that states under which circumstances the old rules might still apply.
For example, my cell phone plan was phased out in the past few years. All existing subscribers to that plan were "grandfathered in," meaning we could still use the old plan, even though no new members would be added to it. Jeff's post was along the same lines, indicating that no new mods would be added, but all existing ones would retain their mod status.
To be "grandfathered in" to something means that:
a) for whatever reason, you currently have some permission, ability, or access.
b) the requirements to be granted that permission, ability, or access are changing, in such a way that you no will no longer meet the requirements.
c) despite not meeting the new requirements, you will be allowed to retain your permission, ability, or access, because you had already been granted it previously.
Grandfathered in is an allusion to grandfather rights, which basically allow someone doing something to carry on doing it, even though new regulations forbid anyone from starting to do that thing.
See here for more.
"Grandfathering" came about in the southern states of the U.S. after the Civil War (and the freedom of slaves). It had to do with "poll taxes" and literacy requirements designed to prevent African-Americans from voting. Because these requirements tended to hurt poor whites as well, these were exempted if their "grandfathers" had been able to vote. (Most newly-freed African-Americans had "slave" grandfathers who couldn't vote.)
"You're grandfathered" means, "the rules don't apply to you" because you have some other "in" (cousin Serena, in this case).
The NOAD reports that grandfather is also an informal verb that means "exempt (someone or something) from a new law or regulation."
Smokers who worked here before the ban have been grandfathered.
