priceless

adjective7

1. •
   So precious as not to be obtainable or sold at any price.

   • For he the night before in Tarquins Tent, / Vnlockt the treasure of his happie state: / VVhat priselesse vvealth the heauens had him lent, / In the possession of his beauteous mate. — 1594
2. •
   (figurative) Held in high regard; treasured.

   • I do not hope that any love and duty I may render in return, will ever make me worthy of your priceless confidence; […] — 1849
3. •
   (informal, figurative) Absurd; ridiculous.

   • “You son of a bitch,” she exploded. “You talk. You, of all people. You. That’s priceless.” — 1946
4. •
   (informal, figurative) Very amusing; hilarious.
5. •
   (informal, figurative) Excellent; fantastic; wonderful.

   • “And have you had a lovely evening?” / “Oh, priceless,” I said. — 1926
6. •
   (rare) Without a price assigned; unpriced.
7. •
   (no longer used) Of no value; valueless; worthless.

   • [H]e thought of his late friendship with anger and held it cheap, a priceless imitation for which perhaps he had given a pure jewel in stupid exchange. — 1905