How many letters does the top answer for “serving an esthetic rather than a useful purpose” have?

The most common answer is decorative (10 letters).

Crossword clue: serving an esthetic rather than a useful purpose

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

decorative 10 letters wn-def

serving an esthetic rather than a useful purpose

ornamental 10 letters wn-def

any plant grown for its beauty or ornamental value