1784, "abstract political science; purely speculative treatment of politics, unrelated to practical matters;" see meta- "transcending, overarching, dealing with the most fundamental matters of" + politics. Based on metaphysics. Related: Metapolitical, which is attested from 1670s in the sense of "outside the realm of politics."
1768, "penitence, spiritual conversion," from Greek metanoia "afterthought, repentance," from metanoein "to change one's mind or purpose," from meta, here indicating "change" (see meta-) + noein "to have mental perception," from noos "mind, thought," which is of uncertain origin.
1833 (Lyell) in the geological sense, "exhibiting change in form or structure," in reference to rock whose form has been changed by heat or pressure, from Greek meta "trans-" (see meta-) + morphē "form," a word of uncertain origin. Earlier (1816) in a theological sense, "characterized by change of form," from metamorphosis + -ic.