How many letters does the top answer for “the act or operation of systematizing.” have?

The most common answer is systematization (15 letters).

Crossword clue: the act or operation of systematizing.

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

systematization 15 letters web-def

systematic organization; the act of organizing something according to a system or a rationale

the act of setting in operation 50% similar → startup

the act or operation of cleansing. 50% similar → mundification

the act or operation of levigating. 50% similar → levigation