How many letters does the top answer for “to become moldy; to be covered or filled, in whole or in part, with a mold.” have?

The most common answer is mould (5 letters).

Crossword clue: to become moldy; to be covered or filled, in whole or in part, with a mold.

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

mould 5 letters web-def

form in clay, wax, etc