How many letters does the top answer for “author of dog years” have?

The most common answer is grass (5 letters).

Crossword clue: author of dog years

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

grass 5 letters wd-fact-v3

narrow-leaved green herbage: grown as lawns; used as pasture for grazing animals; cut and dried as hay

author of a good year 50% similar → crowe

author of reservoir dogs 50% similar → keitel, tarantino

author of straw dogs 50% similar → peckinpah

author of the dogs of riga 50% similar → mankell

author of the heart of a dog 50% similar → bulgakov

author of the year of the hare 50% similar → paasilinna

wrote dog years 50% similar → grass