The man already has offers from 18 bidders who have made 44 bids - the highest till now being that of AUD 10,099 and there are still three days to go.
In his post, the seller "sweatyman" said: "I am selling the word 'The'.
Sweatyman lists the item as "a versatile word that can be used in literally thousands of sentences," the 'Metro' reported.
"Ideal for any situation, this fun-loving item fits perfectly in the palm of your hand, wallet, or purse," he said.
"For example: 'The dogs have escaped again'; 'I will buy some meat from the local deli.'; What's the time?'" he wrote on eBay.
The seven-day bidding began at 0.99 cents and the seller won't accept returns for the item.