A person who posts on a blog thread, in the guise of "concern," to disrupt dialogue or undermine morale by pointing out that posters and/or the site may be getting themselves in trouble, usually with an authority or power. They point out problems that don't really exist. The intent is to derail, stifle, control, the dialogue. It is viewed as insincere and condescending.
A concern troll on a progressive blog might write, "I don't think it's wise to say things like that because you might get in trouble with the government." Or, "This controversy is making your side look disorganized."
The cold or flu one gets after flying on a airplane, especially after long flight.
After returning to New York from San Francisco John came down with airplane flu.
On a film set, the next to last shot of the day. The full term is Abby Singer. He was an assistant director famous for announcing the last shot or setup, only to discover the director wanted one more.
"This is the Abby. Warm up the trucks."
On a film shoot, the last shot of the day.
"This shot is "the martini." The next shot is in the glass.