Valeur absolue

Absolute value
Leibniz used the Latin term moles with the meaning of absolute value of a real number.
Absolute value was coined in German as absoluten Betrag by Karl Weierstrass (1815-1897), who wrote: Ich bezeichne den absoluten Betrag einer complex Groesse x mit |x|. [I denote the absolute value of complex number x by |x|.] This citation appeared in a footnote in his memoir, "Zur Theorie der eindeutigen analytischen Functionen," Abhandlungen der Koeniglich Akademie der Wissenschaften (1876). The memoir was reprinted in volume II of his Mathematische Werke (1895) [Julio González Cabillón]. Absoluten Betrage appears in 1876 in the title "Ein allgemeiner Ausdruck für die ihrem absoluten Betrage nach kleinste Wurzel der Gleichung n Grades" by J. König. In 1889, Elements of Algebra by G. A. Wentworth has: "Every algebraic number, as +4 or -4, consists of a sign + or - and the absolute value of the number; in this case 4. The sign shows whether the number belongs to the positive or negative series of numbers; the absolute value shows what place the number has in the positive or negative series." The Century Dictionary (1889-1897) has absolute magnitude, rather than absolute value.