A word I haven't seen for quite a while.
Source: Webster's Revised Unabridged Dictionary (1913)

Moiety \Moi"e*ty\, n.; pl. Moieties. [F. moiti['e], L.
medietas, fr. medius middle, half. See Mid, a., and cf.
Mediate, Mediety.]
1. One of two equal parts; a half; as, a moiety of an estate,
of goods, or of profits; the moiety of a jury, or of a
nation. --Shak.

The more beautiful moiety of his majesty's subject.
--Addison.

2. An indefinite part; a small part. --Shak.

"When they had travelled slowly forward for some short distance, Nell ventured to steal a look round the caravan and observe it more closely. One half of it--that moiety in which the comfortable proprietress was then seated--was carpeted, and so partitioned off at the further end as to accommodate a sleeping-place, constructed after the fashion of a berth on board ship, which was shaded, like the little windows, with fair white curtains, and looked comfortable enough, though by what kind of gymnastic exercise the lady of the caravan ever contrived to get into it, was an unfathomable mystery. "

It was commonly used in social anthropology, at least back in the '60s.

The word sounds ugly to my ear. I've read it over the years and each time have thought what an ugly-sounding word it is. Curious.

It's just one step removed from the French "moitié"
meaning "half," still quite active in that vocabulary.

(edited to put the accent aigu in accurately - Thanks again, Bill, it's fantastically efficient! Easier than cut-and-pasting.)