IPA: /ˈneɪmləsli/
KK: /ˈneɪmləsli/
In a way that does not use or show a name; in an anonymous manner.
The artist namelessly contributed to the project, preferring to remain unknown.
Namelessly → It is formed from "name" (from Old English *nama*, meaning a word by which a person or thing is known) and "-less" (meaning without) and "-ly" (meaning in a manner). The word "namelessly" means in a manner that is without a name or identity.
Think of being 'without a name' ('-less') and how that describes doing something 'in a manner' ('-ly') that lacks identity.