How many letters does the top answer for “take part in a rebellion; renounce a former allegiance” have?

The most common answer is rebel (5 letters).

Crossword clue: take part in a rebellion; renounce a former allegiance

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

rebel 5 letters wn-def

`Johnny' was applied as a nickname for Confederate soldiers by the Federal soldiers in the American Civil War; `greyback