Obol was an ancient Greek currency that was used for small denominations. It was usually made of silver and was about one-sixth of a drachma. Some of the synonyms for the word "obol" could be "coin," "currency," or "money." Other examples could be "denarius," "shekel," "dinar," or "rupee." Some other synonyms could be "cent," "penny," or "nickel." In some cultures, the obol was used to pay for passage to the underworld, which is why it is sometimes referred to as a "charon's obol." However, regardless of its cultural significance, the obol remains an interesting and unique historical currency that has left a lasting legacy.