How many letters does the top answer for “designed to replace or conserve human and especially manual labor” have?

The most common answer is laborsaving (11 letters).

Crossword clue: designed to replace or conserve human and especially manual labor

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

laborsaving 11 letters wn-def

designed to replace or conserve human and especially manual labor

laboursaving 12 letters wn-def

designed to replace or conserve human and especially manual labor