One after the other

• One after another, as in a series
• In a specific order

Wiktionary Word definitions in Wiktionary
a. (context chiefly legal English) Point by point; sequential. adv. One after another, in order; taking one topic or subject at a time in an order; sequentially.

WordNet Word definitions in WordNet
adv. in a series; one after another

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Seriatim \Se`ri*a"tim\, adv. [NL.] In regular order; one after the other; severally.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1670s (earlier seratim , c.1500), "one after another," from Medieval Latin seriatim , from Latin series (see series ).

Wikipedia Word definitions in Wikipedia
In law, seriatim ( Latin for "in series") indicates that a court is addressing multiple issues in a certain order, such as the order that the issues were originally presented to the court.