The state, quality, or condition of being foolishly bold or reckless; the practice or display of foolhardy behavior.
Foolhardy plus the suffix '-ship' (from Old English 'scipe', denoting state, condition, or office). This rare or archaic formation follows the pattern of creating abstract nouns about conditions or states.
Foolhardiship is so rare it barely appears in modern English—it's a Victorian or earlier construction that shows how English speakers kept creating new words to describe foolish boldness from slightly different angles.
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