How do I add a "word" after the name of artists?

[LyricsLover]

Use Convert Tag -> Tag and the
Field:
ARTIST
and the format string
%ARTIST% YourWord

@Moxa33

at the end of all the artists in my database

You don't add it to your database. You add the word to the tag ARTIST.
This tag is part of the metadata inside your files.

BTW
This is also covered in the FAQ:

Actions and batch-operations

How to append the string " xyz" to the content of a tag field? Create a new action in an existing action group and choose Format value as action type. Field specifies the tag field the formatting rule should be applied to. Format string must have the field placeholder for the field selected above and the string which should be appended. Example: If you want to append the string " xyz" to the current value of the comment field: Action type: Format value Field: COMMENT Format string: %com…