How many letters does the top answer for “a political system governed by old men” have?

The most common answer is gerontocracy (12 letters).

Crossword clue: a political system governed by old men

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

gerontocracy 12 letters wn-def

a political system governed by old men

a political system governed by a woman 50% similar → gynarchy, gynecocracy