Having bones removed, or having a specified type of bone structure.
From Old English 'ban' meaning bone, with the suffix '-ed' indicating past participle or adjectival form. The culinary sense of 'having bones removed' developed in the 16th century.
Interestingly, 'boned' can mean both having bones (as in 'well-boned') and having bones removed (as in 'boned fish'), making it a classic example of how context determines meaning in English. The word also spawned the slang phrase 'getting boned' meaning being disadvantaged or cheated.
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