How many letters does the top answer for “the act of producing offspring or multiplying by such production” have?

The most common answer is multiplication (14 letters).

Crossword clue: the act of producing offspring or multiplying by such production

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

multiplication 14 letters wn-def

the act of producing offspring or multiplying by such production

propagation 11 letters wn-def

the act of producing offspring or multiplying by such production