Intermediate state or interval; most often referring to the period between death and rebirth.
There are six bardos:
1. Bardo of birth, skye ba'i bar do
2. Bardo of dreams, mi lam bardo
3. Bardo of meditation, sam gtan gi bar do
4. Bardo of the moment before death, 'chi kha'i bar do
5. Bardo of dharmata or suchness, chos nyi bar do
6. Bardo of becoming, srid pa'i bar do

See books on death & dying