σφόνδυλος

Etymology
The formation is similar to and, probably first from a noun. Sometimes connected with words like, and , but this is mere speculation. The variation σφ/σπ points to a origin.

Noun

 * 1) vertebra (especially the cervical vertebrae)
 * 2) joint (especially of a scorpion's tail)
 * 3) tambour
 * 4) spindle whorl
 * 5) whorl (botany)
 * 6) voting pebble