diptych

Meanings

1. A writing tablet consisting of two leaves of rigid material connected by hinges and shutting together so as to protect the writing within.
2. A picture or series of pictures painted on two tablets, usually connected by hinges.
3. A double catalogue, containing in one part the names of living, and in the other of deceased, ecclesiastics and benefactors of a church.
4. A catalogue of saints.
5. Artistically-wrought tablets distributed by consuls, etc. of the later Roman Empire to commemorate their tenure of office; hence (transferred sense) a list of magistrates.
6. A novel published in two volumes forming one continuous story (as opposed to a duology or dilogy).
7. A literary work consisting of two contrasting parts, such as a narrative telling the same story from two opposing points of view.
8. Any work made up of two parts treating complementary or contrasting aspects of one general topic.

Etymology

From Late Latin diptycha, plural, from Ancient Greek, neuter plural of δίπτυχος (díptukhos, “folded, doubled”), from δι- (di-) + πτυχή (ptukhḗ, “fold, layer”).