c.1300, from Late Latin transmigrationem (nominative transmigratio) "change of country," noun of action from past participle stem of Latin transmigrare "to wander, to migrate," from trans- "over" (see trans-) + migrare "to migrate" (see migration). Originally literal, in reference to the removal of the Jews into the Babylonian captivity; general sense of "passage from one place to another" is attested from late 14c.; sense of "passage of the soul after death into another body" first recorded 1590s.
transmigration trans·mi·gra·tion (trāns'mī-grā'shən, trānz'-)
Movement from one site to another, which may entail the crossing of some usually limiting membrane or barrier, as in diapedesis.