PRICELESS

adj. 1 costly, dear, expensive, high-priced, valuable, invaluable, precious, inestimable, incalculable; irreplaceable, unique The vaults in the Vatican contain a king's ransom in priceless jewels 2 hilarious, riotous, (screamingly) funny, side-splitting, hysterical, droll, comical, amusing The expression on his face when he realized it was a joke was priceless