Able to be defended, protected, or justified with good reasons.
From Late Latin defensibilis, derived from Latin defendere meaning 'to ward off' or 'protect,' combined with -ible (suffix meaning 'capable of'). The term evolved in medieval English to describe positions that could be physically held in battle, then expanded to mean intellectually or morally justifiable.
A defensible position in chess is different from a defensible position in an argument, yet both use the same word—one is about physical space, the other about logic. This shows how language stretches a single idea across completely different domains.
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