According to information found, among other places, in this question, the name Borg is an abbreviated version of Cyborg, referring to the nature of the Borg.
As can also be found in various sources, for instance cited by Memory Alpha, the Borg were originally intended to be an insectoid species. This is in line with the parasite bugs from TNG: Conspiracy having been planned as the first Borg invasion wave (although this latter claim is not necessarily trustworthy).
In any case, while I have read about the Borg being originally planned as an insectoid species, they seem to be invariably referred to as Borg. Based on the aforementioned ethymology of that name, however, it is unlikely the originally planned insectoid species would have been called Borg, as well.
Did the Borg have another name then used by the production team and if so, what was it?