When a trans person for whatever reason has to use a deadname after already having an actual name.
Derived from deadname, zombies being undead creatures who remain "alive" while supposed to be dead.
Reasons are varied but common ones include but are not limited to:
1) Financial inability to transition
documentation.
2) Legal issue such as transition not being allowed by law.
3) Semi-closet, when transition has only happened under certain social situations because of safety, employment, or other reasons.
4)
Social media companies policies
This list is not exhaustive.
Zombienames are no quite deadnames and thus the person must still be using them in so fashion, even to refer to themselves, for them to be zombiename.
For example, a
social media account with a deadname is one that is kept as an archive, a zombiename account either is minimally active or the main account.