Short for "Squint Intern". Can refer to any number of interns to Dr. Temperance Brennan at the Jeffersonian Institute on the TV show Bones. They all have backgrounds in, or are studying, forensic anthropology. At first, there was only one, Zack Addy, but when he no longer worked at the Jeffersonian, he was replaced by a cycle of numerous "squinterns".
Dr. Saroyan: Dr. Brennan, you could use a second pair of eyes. We happen to be squintern-free.
Professor Jude: There you go! I will be your squintern.