Having a thick, short neck like a bull; heavily muscled in the neck area.
From 'bull' (the animal) + 'necked' (having a neck of a specified kind). The compound emerged in the 1800s to describe people or animals with characteristically thick, powerful necks similar to cattle.
Bullnecked was a favorite descriptor in 19th-century literature for intimidating characters—it signals both physical power and a certain stubborn obstinacy, since bulls are famously headstrong creatures.
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