"tree of the genus Acer," c. 1300, mapel, from Old English mapultreow "maple tree," also mapolder, mapuldre, related to Old Norse möpurr, Old Saxon mapulder, Middle Low German mapeldorn, from Proto-Germanic *maplo-. There also was a Proto-Germanic *matlo- (source also of Old High German mazzaltra, German maszholder), but the connection and origins are mysterious.
Native to northern temperate regions, some of the species are valued for their wood, some for their sugar, some as shade or ornamental trees. The forms in -le are from c. 1400. Formerly with adjectival form mapelin (early 15c.; Old English mapuldern). Maple syrup attested from 1824, American English (earlier maple molasses, 1804). The maple leaf is mentioned as the emblem of Canada from 1850 (an 1843 Canadian source says it "has been adopted as an emblem by our French Canadian brethren").
1560s, from hard (adj.) + wood (n.). That from deciduous trees, as distinguished from that from pines and firs. Bartlett ("Dictionary of Americanisms," 1848) defines it as "A term applied to woods of solid texture that soon decay, including generally, beech, birch, maple, ash, &c. Used by shipwrights and farmers in Maine, in opposition to oak and pine."
"tree of the genus Platanus," native to Persia and the Levant, late 14c., from Old French plane, earlier plasne (14c.), from Latin platanus, from Greek platanos, earlier platanistos "plane tree," a species from Asia Minor, associated with platys "broad" (from PIE root *plat- "to spread") in reference to its leaves. Applied since 1778 in Scotland and northern England to the "sycamore" maple (mock-plane), whose leaves somewhat resemble those of the true plane tree. Compare sycamore.
A Biblical word, originally used for a wide-spreading shade tree with fig-like fruit (Ficus sycomorus) common in Egypt, Palestine, Syria, etc., whose leaves somewhat resemble those of the mulberry; applied in English from 1580s to a large species of European maple (also plane-tree), perhaps because both it and the Biblical tree were notable for their shadiness (the Holy Family took refuge under a sycamore on the flight to Egypt), and from 1814 to the North American shade tree that also is called a buttonwood, which was introduced to Europe from Virginia 1637 by John Tradescant the Younger).
Spelling apparently influenced by sycamine "black mulberry tree," which is from Greek sykcaminos, which also is mentioned in the Bible (Luke xvii.6). For the sake of clarity, some writers have used the more Hellenic sycomore in reference to the Biblical tree.
Its Old World home was India (Alexander the Great's companions marveled at the "honey without bees") and it remained exotic in Europe until the Arabs began to cultivate it in Sicily and Spain; not until after the Crusades did it begin to rival honey as the West's sweetener. The Spaniards in the West Indies began raising sugar cane in 1506; first grown in Cuba 1523; first cultivated in Brazil 1532. The reason for the -g- in the English word is obscure (OED compares flagon, from French flacon). The pronunciation shift from s- to sh- is probably from the initial long vowel sound syu- (as in sure).
As a type of chemical compound from 1826. Slang "euphemistic substitute for an imprecation" [OED] is attested from 1891. As a term of endearment, first recorded 1930. Sugar-cane is from 1560s. Sugar-maple is from 1731. Sugar loaf was originally a moulded conical mass of refined sugar (early 15c.); now obsolete, but sense extended 17c. to hills, hats, etc. of that shape.