How many letters does the top answer for “being of no value; having no worth.” have?

The most common answer is valueless (9 letters).

Crossword clue: being of no value; having no worth.

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

valueless 9 letters web-def

of no value

of no value or worth 60% similar → bastardly, mean

having worth or merit or value 50% similar → worthful