Definition
An order (rite) is an established order of some repeated action. Anything at all that is ordered can be called an order.
An order of service is a sequential, detailed exposition of the content of some divine service.
The sacraments too are performed according to an established order, or in other words — an order of service.
In the Church Everything Must Be Done in Order
“Let all things be done decently and in order” (1 Cor. 14:40) (Greek: κατὰ τάξιν — “according to order”)
“But we command you, brethren, in the name of our Lord Jesus Christ, that you withdraw from every brother who walks disorderly and not according to the tradition which he received from us” (2 Thess. 3:6)
“For we hear that there are some who walk among you in a disorderly manner, not working at all, but are busybodies” (2 Thess. 3:11)