Junketeer is a noun that refers to a person who regularly goes on trips at another’s expense.
The root word of junketeer is junket, a word of Middle English origin. A junket is a trip at the expense of others. A junketer is someone who routinely takes these trips. Example:
After all those years as a traveling journalist, Carl had gotten used the life of a junketeer. So much so that these days he resents having to pay his own air fare.