How many letters does the top answer for “void of feeling; not susceptible of deep emotion; passionless; indifferent.” have?

The most common answer is apathetic (9 letters).

Crossword clue: void of feeling; not susceptible of deep emotion; passionless; indifferent.

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

apathetic 9 letters web-def

marked by a lack of interest

apathetical 11 letters web-def

Void of feeling; not susceptible of deep emotion; passionless; indifferent.