grapefruit (n.)youdaoicibaDictYouDict
1814, from grape + fruit. Said to have been so called for its taste, or perhaps because it grows in clusters. Perhaps a marketing name; it was known by various names (pomelo, shaddock) before the current one emerged. The fruit itself was known since 1693 (in Hans Sloane's catalogue of Jamaican plants); presumably it originated in Jamaica from chance hybrids between other cultivated citrus. An ornamental plant chiefly at first, not much eaten until late 19c.
mule (n.1)youdaoicibaDictYouDict
"offspring of donkey and horse," from Old English mul, Old French mul "mule, hinny" (12c., fem. mule), both from Latin mulus (fem. mula) "a mule," probably from a pre-Latin Mediterranean language.
The mule combines the strength of the horse with the endurance and surefootedness of the ass, and is extensively bred for certain employments for which it is more suited than either; it is ordinarily incapable of procreation. With no good grounds, the mule is a proverbial type of obstinacy. [OED]
Properly, the offspring of a he-ass and a mare; that of a she-ass and a stallion is technically a hinny. Used allusively of hybrids and things of mixed nature. As a type of spinning machine, attested from 1797 (so called because a hybrid of distinct warp and woof machines). Meaning "obstinate, stupid, or stubborn person" is from 1470s; that of "narcotics smuggler or courier" first attested 1935.