Rich and not sweet, with pale yellow-green flesh around one large stone. It is sold hard: leave it at room temperature until it softens, then it goes on toast, into salads and into milkshakes.
牛油果 (literally 'butter fruit') is the everyday colloquial name for avocado in mainland China. The formal/scientific name is 鳄梨 ('crocodile pear'), but it appears almost only on labels and in Taiwan, where 酪梨 is also common.
memory
牛油 means 'butter' and 果 means 'fruit' - think of avocado's rich, buttery flesh.