badger

From Middle English bageard, "marked by a badge," built from bage ("badge") plus the suffix -ard. The name points to the white blaze on the animal's face, like a badge pinned to its head. It replaced an older English word, brock, from Old English brocc.

The word simply moved in to replace brock, the older Old English name for the animal, once the badge-based nickname caught on in Middle English.

Its root badge ties it directly to the everyday word for an identifying emblem or pin — the animal was, in effect, nicknamed for its markings.