Insatiable means incapable of being satisfied or appeased.
Insatiable is an adjective.
Synonyms: greedy, gluttonous, bottomless, voracious, unquenchable, unappeasable, limitless, ravenous.
Antonyms: satisfiable, quenchable, satiable.
Mr.Naveen's desire for money is insatiable even though he has more money than he can spend in his lifetime.
The manager was happy to report that the public appears to have an insatiable appetite for their product.
No one can understand Durga's insatiable need to collect gum wrappers.