late 14c., accusacioun, "charge of wrongdoing," from Old French acusacion "charge, indictment" (Modern French accusation) or directly from Latin accusationem (nominative accusatio) "formal complaint, indictment," noun of action from past-participle stem of accusare "call to account, make complaint against," from ad causa, from ad "with regard to" (see ad-) + causa "a cause; a lawsuit" (see cause (n.)). The meaning "that which is charged (against someone)" is from early 15c.

"the meeting of an accusation by a counter-accusation," 1610s, from French récrimination, from Medieval Latin recriminationem (nominative recriminatio), noun of action from past participle stem of recriminari "to make charges against" (see recriminate).

early 14c., chalenge, "something one can be accused of, a fault, blemish;" mid-14c., "false accusation, malicious charge; accusation of wrong-doing," also "act of laying claim" (to something), from Anglo-French chalenge, Old French chalonge "calumny, slander; demand, opposition," in legal use, "accusation, claim, dispute," from Anglo-French chalengier, Old French chalongier "to accuse, to dispute" (see challenge (v.)). The accusatory connotations faded 17c. The meanings "an objection" in law, etc.; "a calling to fight" are from mid-15c. The sense of "difficult task" is by 1954.

"slanderous, using calumny," late 15c., from Latin calumniosus, from calumnia "slander, false accusation" (see calumny). Related: Calumniously; calumniousness.

c. 1600, "containing an accusation," from Latin accusatorius "of a prosecutor, relating to prosecution; making a complaint," from accusare "call to account, make complaint against" (see accuse). Related: Accusatorial (1801); accusatorially.

1620s, from sycophant + abstract noun suffix -cy, or else from Latin sycophantia, from Greek sykophantia "false accusation, slander; conduct of a sycophant," from sykophantes.

"knowingly utter false charges," 1550s, from Latin calumniatus, past participle of calumniari "to accuse falsely," from calumnia "slander, false accusation" (see calumny). A doublet of challenge. Related: Calumniated; calumniating.

"act of exonerating or of discharging or freeing; state of being discharged or freed from an accusation, obligation, debt, etc.," 1630s, from Late Latin exonerationem (nominative exoneratio) "an unloading, lightening," noun of action from past-participle stem of exonerare "free from a burden" (see exonerate).

early 15c., legal, "a charge, a formal accusation," from Old French surmise "accusation," noun use of past participle of surmettre (see surmise (v.)). Meaning "inference, guess" is first found in English 1580s.

Then felt I like some watcher of the skies

When a new planet swims into his ken;

Or like stout Cortez, when with eagle eyes

He stared at the Pacific—and all his men

Look'd at each other with a wild surmise—

Silent, upon a peak in Darien.

[Keats]

late 14c., enpechement "accusation, charge," from Old French empeechement "difficulty, hindrance; (legal) impeachment," from empeechier "to hinder, impede" (see impeach). As a judicial proceeding on charges of maladministration against a public official, from 1640s.