■ noun
1》 short for ~ number .
2》 Christian Church, historical a service book, especially one with the forms of service used at ordinations.
■ adjective
1》 relating to order in a series.
2》 Biology relating to a taxonomic order.
Origin
ME: the noun from med. L. ~e ; the adjective from late L. ~is 'relating to order', from L. ordo , ordin- (see order ).