From Middle English lef, leef, from Old English lēaf, from Proto-West Germanic *laub, from Proto-Germanic *laubą (“leaf”), from Proto-Indo-European *lowbʰ-o-m, from *lewbʰ- (“to cut off”). Cognates Cognate with Scots leaf (“leaf”), Yola laafe (“leaf”), North Frisian luuf (“leaf”), Saterland Frisian Loof (“leaf”), West Frisian leaf (“leaf”), Cimbrian loap (“leaf”), Dutch loof (“foliage”), German Laub (“leaves”), German Low German Loov (“leaf”), Luxembourgish Laf (“foliage, leaves”), Mòcheno lap (“leaf”), Vilamovian łaub, łaup, łojp (“leaf”), Danish and Norwegian Bokmål løv (“leaf”), Faroese leyv (“leaf”), Icelandic lauf (“leaf”), Norwegian Nynorsk lauv (“leaf”), Swedish löv (“leaf”), Gothic 𐌻𐌰𐌿𐍆𐍃 (laufs, “leaf”); also Irish luibh (“herb, plant”), Latin liber (“bast; book”), Albanian labë (“rind”), Lithuanian lúobas (“bark; bast”), Polish łub (“bark”), Russian луб (lub, “bast”). (Internet slang: Canadian): In reference to the maple leaf as national symbol.
The usually green and flat organ that represents the most prominent feature of most vegetative plants.
Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close (less than half a meter) above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them.2013 May-June, William E. Conner, “An Acoustic Arms Race”, in American Scientist, volume 101, number 3, pages 206–7:
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Biology, Botany, Natural sciences A foliage leaf or any of the many and often considerably different structures it can specialise into.
Heretofore advertisers have had to buy and pay for a leaf — two pages.1900, Profitable Advertising, volume 10, number 2, page 893:
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A sheet of any substance beaten or rolled until very thin.
gold leaf
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One of the individual flat or curved strips of metal, typically made of spring steel, that make up a leaf spring.
Lumbering down a precipitous "slideway," the Thornycroft broke two main leaves in the back spring[.]1931, Ion L. Idriess, Lasseter's Last Ride, Sydney: Angus and Robertson, page 52:
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In plural Tea leaves.
8
A flat section used to extend the size of a table.
9
A moveable panel, e.g. of a bridge or door, originally one that hinged but now also applied to other forms of movement.
Plural leaves or leafs
The train car has one single-leaf and two double-leaf doors per side.
The bridge shear locks were repaired and the long ends of the shear locks shortened about two inches to eliminate butting of the bridge leafs against each other.1914, Department of Bridges, City of New York, Report, page 90:
4 more examples
It will be noted that the pivotal mounting of the cylinders is such that the cylinders have their greatest leverage (i.e., exert the greatest door-opening force) when the door leafs 24, 28 are closed because the cylinders are generally perpendicular to the closed leafs. This is desirable because the load on the leafs is the greatest when they are closed due to air pressure. As the leafs begin to open and this air pressure decreases, the opening force exerted by the cylinders on the door leafs decreases and the opening speed of the leafs increases.1992 July 21, William R. Kennedy, John M. Kennedy, Power mine door system, US Patent 5,222,838:
THE NTSB RECOMMENDS THAT THE U.S. COAST GUARD: REQUIRE OWNERS/OPERATORS OF BASCULE BRIDGES TO INSTALL CAUTION LIGHTS AND DAYLIGHT MARKINGS AT ELEVATION POINTS ON BRIDGE LEAFS WHERE THEY PROTRUDE OVER NAVIGABLE CHANNELS TO IDEN TIFY^([sic]) TO MARINERS THE POINT AT WHICH FULL SKYWARD CHANNEL CLEARANCE IS NOT AVAILABLE TO TRANSITING VESSELS: THE LIGHTS SHOULD ACTIVATE WHEN THE BRIDGELEAFS ARE IN THE NORMAL FULLY OPEN POSITION.[…]THE NTSB RECOMMENDS THAT THE U.S. COAST GUARD: REQUIRE THAT BRIDGE OWNERS/OPERATORS PROVIDE IN BASCULE BRIDGE PERMIT APPLICATIONS THE ANGLE OF THE BRIDGELEAF(S). THE MAXIMUM VERTICAL CLEARANCE AT THE FENDERS AND AT THE BRIDGELEAF ENDS, AND THE EXTENT OF HORIZONTAL CHANNEL CLEARANCE OVER WHICH FULL SKYWARD CLEARANCE IS AVAILABLE WHEN THE BRIDGE LEAFS ARE IN THE FULLY OPEN POSITION.1993, Department of Transportation and Related Agencies Appropriations for 1994: Hearings Before a Subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Third Congress, First Session, Washington, D.C.: U.S. Government Printing Office, →ISBN, page 136:
The four separate segments of the movable bridge span, known as bridge leafs, were alternately rehabilitated while maintaining upper-level roadway and pedestrian traffic on one-half of the bridge and waterway traffic on one-half of the river channel.1993, Realty and Building, page 20:
The hydraulic system lifts and rotates two 413-ft (126-m) bridge leafs, each weighing 7,500 tons, in just four minutes.1993, The Americana Annual: An Encyclopedia of Current Events, Grolier, →ISBN, →ISSN, →LCCN, page 224:
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Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Sciences In a tree, a node that has no descendants.
The algorithm pops the stack to obtain a new current node when there are no more children (when it reaches a leaf).2011, John Mongan, Noah Kindler, Eric Giguère, Programming Interviews Exposed:
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The layer of fat supporting the kidneys of a pig, leaf fat.
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One of the teeth of a pinion, especially when small.
Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Programming, Sciences A particular value of the EAX register when a program runs the CPUID instruction; each leaf represents a different category of information returned about the processor.
X86_FEATURE_HETERO_CORE_TOPOLOGY is used to identify whether the processor support heterogeneous core type by reading CPUID leaf Fn_0x80000026_EAX and bit 30. if the bit is set as one, then amd_pstate driver will check EBX 30:28 bits to get the core type.2024 May 7, Perry Yuan, “[PATCH 00/11] AMD Pstate Driver Fixes and Improvements”, in Kernel Lore:
From Middle English lef, leef, from Old English lēaf, from Proto-West Germanic *laub, from Proto-Germanic *laubą (“leaf”), from Proto-Indo-European *lowbʰ-o-m, from *lewbʰ- (“to cut off”). Cognates Cognate with Scots leaf (“leaf”), Yola laafe (“leaf”), North Frisian luuf (“leaf”), Saterland Frisian Loof (“leaf”), West Frisian leaf (“leaf”), Cimbrian loap (“leaf”), Dutch loof (“foliage”), German Laub (“leaves”), German Low German Loov (“leaf”), Luxembourgish Laf (“foliage, leaves”), Mòcheno lap (“leaf”), Vilamovian łaub, łaup, łojp (“leaf”), Danish and Norwegian Bokmål løv (“leaf”), Faroese leyv (“leaf”), Icelandic lauf (“leaf”), Norwegian Nynorsk lauv (“leaf”), Swedish löv (“leaf”), Gothic 𐌻𐌰𐌿𐍆𐍃 (laufs, “leaf”); also Irish luibh (“herb, plant”), Latin liber (“bast; book”), Albanian labë (“rind”), Lithuanian lúobas (“bark; bast”), Polish łub (“bark”), Russian луб (lub, “bast”). (Internet slang: Canadian): In reference to the maple leaf as national symbol.
1
To produce leaves; put forth foliage.
Then flowered the mead, then leafed all 'Twas caused by the runic lay.1828, Thomas Keightley, The Fairy Mythology, volume I, London: William Harrison Ainsworth, page 164:
2
To divide (a vegetable) into separate leaves.
The lettuce in our burgers is 100% hand-leafed.
3
Informal, Uncommon To play a prank on someone by throwing a large clump or collection of leaves at them.