The plural of collarbone; the pair of long, slender bones that connect the breastbone to the shoulder blades.
From 'collar' (because the bone sits at the neck/shoulder region where a collar would be) and 'bone'. The anatomical term became standard in English medical vocabulary by the 1600s, referencing both the position and shape of this clavicle.
Your collarbones are one of the only bones you can feel directly under your skin without any muscle covering—they're so accessible that some people use them as a beauty standard in fashion, which is why models are often judged by their 'bone structure.'
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