How many letters does the top answer for “of or relating to or suffering from neurasthenia” have?

The most common answer is neurasthenic (12 letters).

Crossword clue: of or relating to or suffering from neurasthenia

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

neurasthenic 12 letters wn-def

a person suffering a nervous breakdown

of or relating to or suffering from neuralgia 50% similar → neuralgic