How many letters does the top answer for “having a bill like that of a duck..” have?

The most common answer is duckbilled (10 letters).

Crossword clue: having a bill like that of a duck..

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

duckbilled 10 letters web-def

small densely furred aquatic monotreme of Australia and Tasmania having a broad bill and tail and webbed feet; only spec

having a bill like that of the stork. 60% similar → storkbilled

having a lamellate bill, as ducks and geese. 50% similar → lamellirostral

having a toothed bill, like that of a toucan. 50% similar → serratirostral