Word that means the same thing even with several letters added?

Synonym with added letters
– Synonym with added letters

Word that stays the same despite added letters
– Word that stays the same despite added letters

Term that doesn’t change with extra letters
– Term that doesn’t change with extra letters

Jargon with superfluous characters
– Jargon with superfluous characters

A word that remains constant regardless of extra letters
– A word that remains constant regardless of extra letters

Lexicon with unnecessary letters
– Lexicon with unnecessary letters

Vocabulary term unaffected by additional letters
– Vocabulary term unaffected by additional letters

Term that is unchanged by the addition of several letters.
– Term that is unchanged by the addition of several letters.