Etymology
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arraign (v.)
late 14c., araynen, "to call to account," also "to call up on a criminal charge," from Old French araisnier "speak to, address; accuse (in a law court)," from Vulgar Latin *arrationare, from Latin adrationare, from ad "to" (see ad-) + *rationare, from ratio "argumentation; reckoning, calculation" (from rat-, past participle stem of reri "to reckon, calculate," also "think" (from PIE root *re- "to reason, count"). The unetymological -g- is a 16c. overcorrection based on reign, etc. Related: Arraigned; arraigning.
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arraignment (n.)

mid-15c., from Old French araisnement, from araisnier(see arraign).

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*re- 

*rē-, Proto-Indo-European root meaning "to reason, count;" a variant of PIE root *ar-, also arə-, "to fit together." 

It forms all or part of: Alfred; arraign; arithmetic; Conrad; dread; Eldred; Ethelred; hatred; hundred; kindred; logarithm; Ralph; rate (n.) "estimated value or worth;" rathskeller; ratify; ratio; ration; read; reason; rede; rhyme; riddle (n.1) "word-game;" rite; ritual.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit radh- "to succeed, accomplish;" Greek arithmos "number, amount;" Latin reri "to consider, confirm, ratify," ritus "rite, religious custom;" Old Church Slavonic raditi "to take thought, attend to;" Old Irish im-radim "to deliberate, consider;" Old English rædan "to advise, counsel, persuade; read;" Old English, Old High German rim "number;" Old Irish rim "number," dorimu "I count."

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accuse (v.)
c. 1300, "charge (with an offense, fault, error, etc.), impugn, blame," from Old French acuser "to accuse, indict, reproach, blame" (13c., Modern French accuser), earlier "announce, report, disclose" (12c.), or directly from Latin accusare "to call to account, make complaint against, reproach, blame; bring to trial, prosecute, arraign indict," from ad causa, from ad "with regard to" (see ad-) + causa "a cause; a lawsuit" (see cause (n.)). "Accuse commonly, though not invariably, expresses something more formal and grave than charge" [Century Dictionary, 1902]. Related: Accused; accusing; accusingly.
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