How many letters does the top answer for “wrote ice age” have?

The most common answer is romano (6 letters).

Crossword clue: wrote ice age

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

romano 6 letters wd-fact-v3

author of ice age 50% similar → romano

composer of ice age 50% similar → leary

director of ice age 50% similar → leary, romano

wrote axial age 50% similar → jaspers

wrote the age of reason 50% similar → paine

wrote the ice-maiden 50% similar → andersen