"headless," 1731, from French acéphale + -ous or directly from Late Latin acephalus, from Greek akephalos. See a- (3) "not" + cephalo- "head." Principally in botany and zoology, but also "without a leader" (1751). Acephali as the name of a fabulous race of men with no heads, said by ancient writers to inhabit part of Africa, is attested from c. 1600, from Late Latin plural of acephalus, from Greek akephalos; the name also appears in Church history in reference to sects that refused to have priests or bishops (1620s). Related: Acephalian (1580s); acephalic (1650s).
late 14c., name of the potter's field near Jerusalem that was purchased with the money Judas Iscariot took to betray Jesus, literally "place of bloodshed," from Greek Akeldama, rendering an Aramaic (Semitic) name akin to Syriac haqal dema "the field of blood." So called for being purchased with the blood-money.
word-forming element in Modern Latin making names for orders and classes in zoology (Crustacea, Cetacea, etc.), from Latin -acea, neuter plural of -aceus "belonging to, of the nature of" (enlarged from adjectival suffix -ax, genitive -acis). The names are thus formally adjectives, Latin animalia "animals" (a neuter plural noun) being understood. Thus Crustacea "shellfish" are *crustacea animalia "crusty animals." In botany, the suffix is -aceae, from the fem. plural of -aceus, forming orders or families of plants (Rosaceae, etc.) with a presumed plantae "plants," which is a fem. plural.
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.