Capable of being attacked or vulnerable to being criticized, challenged, or assaulted.
From 'attack' (from Italian 'attaccare,' originally meaning to fasten or join in battle) plus the suffix '-able' meaning 'capable of being.' The word emerged in English in the 1600s as military vocabulary expanded.
Ideas and arguments are often more 'attackable' than physical objects, which is why this word gets used more in debate and criticism than in military contexts—showing how English repurposes combat language for intellectual battles.
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