origin: there bloody well isn't one.
I think I'll take a tip from ellesieg's style here, since this word is a personal fetish of mine, and yet...is rather poorly defined. Really, I'm a sucker for most anything fictional that is connected to "droid", or essentially, an artificial being. The same goes for "borg", which seems to be a suffix for mechanical.
Now, follow me. A robot is a machine programmed with a certain level of ability, but not capable of thinking for itself and does not need to resemble a human (such as: J.A.R.V.I.S.). An android is an entirely mechanical body that resembles a human being as closely as possible, including intelligence (example: Data from Star Trek). A cyborg is part human and part machine (think: Robocop).
So...to me, a mandroid should be a creature constructed of flesh, resembling a person in entirety, such as Dr. Frankenstien's monster or Longshot (from Marvel Comics) -- though technically, it would fall just short of being truly human [insert possible arguments about the soul here]. *Not to be confused with a homunculus, as that would be grown, and is implied to be diminutive in stature.
However, currently, the most likely definition one will find is: “A Mandroid is a heavily armored personal combat suit originally designed and engineered by Stark International for use by S.H.I.E.L.D. (Supreme Headquarters International Espionage Law-enforcement Division).”
That is just wrong. I am shocked and appalled Mr. Stark, because we all know these are "exosuits", and everyone can thank the country of Japan for their fine work over their long-standing obsession with that idea!
origin: Matt. 6:24; Luke 16:9,11,13. < Late Latin < Greek < Aramaic = māmōnā riche
Speaking of people like Longshot, whose dimension is run by a being so hellbent on greed that the entire place is named after him and worship is a way of life, via the mass media of violent, reality television competitions (remind you of a slightly more familiar dimension..hmm?). Nor is it that dissimilar from a certain sluggish alien known as Jabba the Hut who occupies the universe with a couple of "plucky" Droids (there's that prefix again).
No one knows mammon like these high mucky-mucks!
1. riches or wealth regarded as a source of evil and corruption
2. worldly gain personified as a false god in the New Testament
3. avarice or greed
Check, check, check!!
Bonus points for both also having creepy platforms upon which they perch, and glare down with the clarity of forbearance that such words stemming from the bible can afford. Like, oh yeah, maybe one can overdo it with the mammon.