IPA: /ˌdɛrɪˈveɪʃən/
KK: /dɛrəˈveɪʃən/
The process of forming a new word or expression from an existing word or base, often by adding prefixes or suffixes, or changing its form.
The derivation of the word 'happiness' comes from the root 'happy' with the addition of the suffix '-ness'.
Derivation → It is formed from "de-" (meaning from or down from) and "rivare" (meaning to flow). The word refers to the process of obtaining something from a source, as if something is flowing down from its origin.
Think of something 'flowing down' ('rivare') from a source ('de-') — that's how derivation means obtaining something from its origin.