IPA: /ˈædɪtɪvli/
KK: /ˈædɪtɪvli/
In a way that involves adding things together or combining them.
The chemicals were mixed additively to achieve the desired reaction.
Additively → It is formed from "add" (from Latin "addere", meaning to put to) and "-ive" (meaning having the nature of) and "-ly" (meaning in a manner). The word "additively" means in a manner that involves putting together or adding.
Think of 'adding' something together, as 'add' means to put to, and '-ly' indicates the manner of doing it. So, 'additively' means doing something in a way that involves addition.