ἄμπυξ

Etymology
Formerly considered to be a root noun prefixed with ἀμ-, belonging to and, and cognate with 🇨🇬. However, the notion "thick, solid" does not seem to fit the objects in question. A word for such objects is easily borrowed and, according to Beekes, it contains a typical suffix.

Noun

 * 1) woman's diadem, frontlet
 * 2) horse's headband
 * 3) rim of a wheel