Trivia 10-16-17 Greybacks

[ami]

nswer: "Graybacks" was the common name for Pediculus humanus corporis and Pediculus vestimenti--body lice

Source: http://civilwarstudies.org/trivia.shtm#06

Edit - The consensus seems to be that, although Union soldiers used it as a derogatory term to describe Confederate soldiers (implying that the Confederates were always running away, so all that could be seen of them was their backs), Confederates did occasionally use it to describe themselves. So I will accept that as an alternative answer.

hoosier