insatiability; greed for more
Derived from a Chinese historical anecdote; used to describe never being satisfied after gaining something and immediately wanting more. Mostly appears in the idiom 望蜀の思い or in literary writing.
Even after achieving one goal, he immediately pursues the next—truly a case of insatiable ambition.
From a story in the Chinese historical text 'Book of the Later Han': after conquering the region of Long (隴), the general immediately desired Shu (蜀). The phrase 望蜀 (lit. 'gaze at Shu') came to symbolize insatiable ambition.