Etymology Expeditions: Words for Otherness

The word other is from Old English oþer "the second" from PIE  an-tero, the other of two, still seen in the Swedish andra, but in English this meaning was removed to avoid ambiguity, replaced by the word "second." The meaning of "different" is from the 1300s. There are lots of words for otherness, with different connotations, but most of them boil down to the fear of the foreign.

Alien comes from the Latin alienus, belonging to another race, which goes back to alius, "another."

Strange is from Latin extraneus, "foreign, external, from without." It made its way into English through the Old French estrange.

Weird is a fun one. It comes from Old English wyrd "fate, chance, fortune" and the etymology goes back to the Norns (see Old Norse urðr). The PIE root *wert-, to turn, to wind, is the source.

Odd originally meant "constituting of an unit in excess of an even number." The literal meaning is from Old Norse odds,  "point of land, angle." The sense of "strange, peculiar" is from the 1580s, as in "odd man out, unpaired one of three." Odd job also comes from his, as in "not regular." Oddball is also of the same origin, from an a adjective first used by aviators in the 1940s.  (I couldn't find out more about what the aviators used it for, if anyone knows, tell me in the comments.)

Foreign goes back to the Latin foraneus, "on the outside, exterior,"  from foris, "out of doors."

Queer as in "strange, peculiar, eccentric," is from Scottish, perhaps related to German quer "oblique, perverse, odd," from Old High German twerh "oblique," from PIE root *terkw- "to turn, twist, wind" The sense of "homosexual" is from 1922.

Let's end with a positive one: extraordinary. It's from Latin extraordinarius, "out of the common order." We can thank the French for the word's colloquial use as a superlative.

Sources:

http://www.etymonline.com/