How many letters does the top answer for “a coin worth nine pennies” have?

The most common answer is ninepence (9 letters).

Crossword clue: a coin worth nine pennies

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

ninepence 9 letters wn-def

a coin worth nine pennies

a coin worth eight pennies 60% similar → eightpence

a decimal coin worth ten pennies 50% similar → tenpence

an english coin worth half a penny 50% similar → halfpenny