Etymology
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Judaeo- 
also Judeo-, word-forming element meaning "of or pertaining to the Jewish people or religion," from Latin Iudaeus (see Jew (n.)).
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fore- 
Middle English for-, fore-, from Old English fore-, often for- or foran-, from fore (adv. & prep.), which was used as a prefix in Old English as in other Germanic languages with a sense of "before in time, rank, position," etc., or designating the front part or earliest time.
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bio- 
word-forming element, especially in scientific compounds, meaning "life, life and," or "biology, biology and," or "biological, of or pertaining to living organisms or their constituents," from Greek bios "one's life, course or way of living, lifetime" (as opposed to zoe "animal life, organic life"), from PIE root *gwei- "to live." The correct usage is that in biography, but since c. 1800 in modern science it has been extended to mean "organic life," as zoo-, the better choice, is restricted in modern use to animal, as opposed to plant, life. Both are from the same PIE root. Compare biology.
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photo- 

word-forming element meaning "light" or "photographic" or "photoelectric," from Greek photo-, combining form of phōs (genitive phōtos) "light" (from PIE root *bha- (1) "to shine").

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oneiro- 

before vowels oneir-, word-forming element meaning "of or pertaining to a dream or dreams," from Greek oneiros "a dream," a word of uncertain origin, perhaps related to Armenian anurj, Albanian (Gheg) âdërrë.

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techno- 

word-forming element meaning "art, craft, skill," later "technical, technology," from Latinized form of Greek tekhno-, combining form of tekhnē "art, skill, craft in work; method, system, an art, a system or method of making or doing," from PIE *teks-na- "craft" (of weaving or fabricating), from suffixed form of root *teks- "to weave," also "to fabricate."

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for- 

prefix usually meaning "away, opposite, completely," from Old English for-, indicating loss or destruction, but in other cases completion, and used as well with intensive or pejorative force, from Proto-Germanic *fur "before, in" (source also of Old Norse for-, Swedish för-, Dutch ver-, Old High German fir-, German ver-); from PIE *pr-, from root *per- (1) "forward," hence "in front of, before, toward, near, against."

In verbs the prefix denotes (a) intensive or completive action or process, or (b) action that miscarries, turns out for the worse, results in failure, or produces adverse or opposite results. In many verbs the prefix exhibits both meanings, and the verbs frequently have secondary and figurative meanings or are synonymous with the simplex. [Middle English Compendium]

Probably originally in Germanic with a sense of "forward, forth," but it spun out complex sense developments in the historical languages. Disused as a word-forming element in Modern English. Ultimately from the same root as fore (adv.). From its use in participles it came to be an intensive prefix of adjectives in Middle English (for example Chaucer's forblak "exceedingly black"), but all these now seem to be obsolete.

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sy- 
form of syn- before -s- or -z-.
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ker- 
U.S. slang prefix, by 1836 as che-, 1843 as ker-, possibly from influence of German or Dutch ge-, past participial prefixes; or ultimately echoic of the sound of the fall of some heavy body.
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abs- 
the usual form of ab- before -c-, -q-, or -t-.
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