late 13c., "to appoint or admit to the ministry of the Church," from stem of O.Fr. ordener
, from L. ordinare
"put in order, arrange, dispose, appoint," from ordo
) "order." The notion is "to confer holy orders upon" (see order
). Meaning "to decree, enact" is from c.1300; sense of "to set (something) that will continue in a certain order" is from early 14c.