How many letters does the top answer for “inadequate in amount or degree” have?

The most common answer is deficient (9 letters).

Crossword clue: inadequate in amount or degree

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

deficient 9 letters wn-def

inadequate in amount or degree

a small and inadequate amount 50% similar → scarceness, scarcity

in an inadequate manner or to an inadequate degree 50% similar → inadequately

increased in amount or degree 50% similar → elevated