Etymology
Advertisement
Baltic (adj.)
1580s, "pertaining to the brackish sea between the Scandinavian peninsula and Eastern Europe," from Medieval Latin Balticus, perhaps from Lithuanian baltas "white" or Scandinavian balta "belt; strait" (in reference to its narrow entranceway). In German, it is Ostsee, literally "east sea." From 1887 as the name of a language group comprising Lithuanian, Lettish, and Old Prussian.
Related entries & more 
Advertisement
centillion (n.)

in France and U.S., "1,000 to the hundredth power," 1846, from centi- "one hundred" (in reference to the 100 groups of three zeroes it has beyond the first group of three zeroes) + ending from million, etc. Compare French centillion (by 1841). Generally used indefinitely for "a very large number." Related: Centillionth.

Related entries & more 
assortment (n.)
1610s, "action of arranging into kinds or classes," from assort + -ment. Sense of "group of things of the same sort" is attested from 1759; that of "group of arranged things whether of the same sort or not" from 1791.
Related entries & more 
newsgroup (n.)

"internet discussion group within the Usenet system containing messages posted from users in different locations," by 1985, from news (n.), perhaps on the notion of sharing news of a particular topic, + group (n.).

Related entries & more 
troika (n.)
1842, "carriage drawn by three horses abreast," from Russian troika "three-horse team, any group of three," from collective numeral troje "group of three" (from PIE *tro-yo-, suffixed form of *trei-, see three) + diminutive suffix -ka. Sense of "any group of three administrators, triumvirate" is first recorded 1945.
Related entries & more 
Advertisement
decade (n.)

mid-15c., "ten parts" (of anything; originally in reference to the divisions of Livy's history), from Old French décade (14c.), from Late Latin decadem (nominative decas), from Greek dekas (genitive dekados) "group of ten," from deka "ten" (from PIE root *dekm- "ten"). Meaning "period of ten consecutive years" is 1590s in English. Related: Decadal; decadary.

Related entries & more 
Tupi (n.)
a native language group of South America, also Tupian.
Related entries & more 
groupie (n.)
"girl who follows pop groups," 1967, from group (n.) in the pop music sense + -ie. In World War II R.A.F. slang it was short for group captain.
Related entries & more 
Aramaic (adj.)
1824, in reference to the northern branch of the Semitic language group, from Greek Aramaia, the biblical land of 'Aram, roughly corresponding to modern Syria. The place name probably is related to Hebrew and Aramaic rum "to be high," thus originally "highland." As a noun, "the Aramaic langue," from 1833; Aramaic was the lingua franca of the Assyrian empire, the official language of the Persian kingdom, and the daily language of the Jews at the time of Christ.
Related entries & more 
omerta (n.)

Mafia code of obedience to the leader and silence about the organization and its business, 1909, from Italian omertà, a dialectal form of umilta "humility," in reference to submission of individuals to the group interest, from Latin humilitas "lowness, small stature; insignificance; baseness, littleness of mind," in Church Latin "meekness," from humilis "lowly, humble," literally "on the ground," from humus "earth," from PIE root *dhghem- "earth."

Related entries & more 

Page 3