1845 in the biological sense "exhibiting or affected by metabolism," from German metabolisch (1839), from Greek metabolikos "changeable," from metabole "a change, changing, a transition" (see metabolism). Related: Metabolically.
by 1996, from metropolitan + -sexual, ending abstracted from homosexual, heterosexual. Wikipedia defines it as "a portmanteau of metropolitan and heterosexual, coined in 1994 describing a man who is especially meticulous about his grooming and appearance, typically spending a significant amount of time and money on shopping as part of this."
Nevertheless, the metrosexual man contradicts the basic premise of traditional heterosexuality—that only women are looked at and only men do the looking. Metrosexual man might prefer women, he might prefer men, but when all's said and done nothing comes between him and his reflection. [Mark Simpson, "It's a Queer World," 1996]
word-forming element meaning "process of measuring," Middle English -metrie, from French -metrie, from Latin -metria, from Greek -metria "a measuring of," from -metros "measurer of," from metron "measure," from PIE root *me- (2) "to measure."
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."