palmyoudaoicibaDictYouDict[palm 词源字典]
palm: Palm the tree [OE] and the palm of the hand [14] are effectively distinct words in English, but they have the same ultimate source: Latin palma. This originally meant ‘palm of the hand’ (it is related to Irish lám ‘hand’ and Welsh llaw ‘hand’), and the application to the tree is a secondary one, alluding to the shape of the cluster of palm leaves, like the fingers of a hand.

The Latin word was borrowed into the Germanic dialects in prehistoric times in the tree sense, and is now widespread (German palme and Dutch and Swedish palm as well as English palm). English acquired it in the ‘hand’ sense via Old French paume, with subsequent reversion to the Latin spelling. The French diminutive palmette denotes a stylized palm leaf used as a decorative device, particularly on cornices.

It was borrowed into English in the mid-19th century, and is thought to have formed the basis of English pelmet [20].
=> pelmet[palm etymology, palm origin, 英语词源]
palm (n.1)youdaoicibaDictYouDict
"flat of the hand," c. 1300, from Old French palme (Modern French paume), from Latin palma "palm of the hand," also "flat end of an oar; palm tree," from PIE *pel- "to spread out; flat" (cognates: Greek palame "open hand," Old Irish lam, Welsh llaw, Old English folm, Old High German folma "hand," Sanskrit panih "hand, hoof"). Palm oil is earlier in the punning sense of "bribe" (1620s) than in the literal sense of "oil from the fruit of the West African palm" (1705, from palm (n.2)).
palm (n.2)youdaoicibaDictYouDict
tropical tree, Old English palma, Old French palme, both from Latin palma "palm tree," originally "palm of the hand;" the tree so called from the shape of its leaves, like fingers of a hand (see palm (n.1)).

The word traveled early to northern Europe, where the tree does not grow, via Christianity, and took root in the local languages (such as Old Saxon palma, Old High German palma, Old Norse palmr). Palm Sunday is Old English palm-sunnandæg.

In ancient times, a leaf or frond was carried or worn as a symbol of victory or triumph, or on feast days; hence figurative use of palm for "victory, triumph" (late 14c.). Palm court "large room in a hotel, etc., usually decorated with potted palms" first recorded 1908.
palm (v.)youdaoicibaDictYouDict
"impose (something) on (someone)," 1670s, from palm (n.1). Extended form palm off is from 1822.