IPA: /sɪˈnɒnɪməsli/
KK: /sɪˈnɑnɪməsli/
In a way that means the same as another word or phrase.
The two words can be used synonymously in this context.
Synonymously → It is formed from "syn-" (meaning together) and "onymos" (from Greek, meaning name) and the suffix "-ously" (meaning in a manner). The word describes the manner in which two or more words share the same name or meaning together.
Think of words that share the same 'name' ('onymos') 'together' ('syn-') — that's why synonymously means in a way that words have the same meaning.