biohazard n.

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.

c. 1300, name of a game at dice, from Old French hasard, hasart "game of chance played with dice," also "a throw of six in dice" (12c.), of uncertain origin. Possibly from Spanish azar "an unfortunate card or throw at dice," which is said to be from Arabic az-zahr (for al-zahr) "the die." But this is doubtful because of the absence of zahr in classical Arabic dictionaries. Klein suggests Arabic yasara "he played at dice;" Arabic -s- regularly becomes Spanish -z-. The -d was added in French through confusion with the native suffix -ard. Sense evolved in French to "chances in gambling," then "chances in life." In English, sense of "chance of loss or harm, risk" first recorded 1540s.