How many letters does the top answer for “armor plate that protects the arm” have?

The most common answer is brassard (8 letters).

Crossword clue: armor plate that protects the arm

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

brassard 8 letters wn-def

armor plate that protects the arm

armor plate that protects the neck 60% similar → gorget

armor plate that protects the thigh 60% similar → cuisse

armor plate that protects the hip and thigh 50% similar → tuille