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• leaf
  leaf

  noun

  one of the expanded, usually green organs borne by the stem of a plant.
• Leaf
  Leaf

  noun

  Munro 1905–76, U.S. author and illustrator of books for children.

leaf

¹ American  

[leef] / lif /

noun

plural

leaves

1. one of the expanded, usually green organs borne by the stem of a plant.

2. any similar or corresponding lateral outgrowth of a stem.

3. a petal.

   a rose leaf.

4. leaves collectively; foliage.

5. Bibliography. a unit generally comprising two printed, blank, or illustrated pages of a book, one on each side.

6. a thin sheet of metal.

   silver leaf.

7. a lamina or layer.

8. a sliding, hinged, or detachable flat part, as of a door or tabletop.

9. a section of a drawbridge.

10. a single strip of metal in a leaf spring.

11. a tooth of a small gear wheel, as of a pinion.

12. leaf fat.

13. Textiles. shaft.

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verb (used without object)

1. to put forth leaves.

2. to turn pages, especially quickly (usually followed bythrough ).

   to leaf through a book.

verb (used with object)

1. to thumb or turn, as the pages of a book or magazine, in a casual or cursory inspection of the contents.

idioms

1. in leaf, covered with foliage; having leaves.

   the pale green tint of the woods newly in leaf.

2. take a leaf out of / from someone's book, to follow someone's example; imitate.

   Some countries that took a leaf out of American industry's book are now doing very well for themselves.

3. turn over a new leaf, to begin anew; make a fresh start.

   Every New Year's we make resolutions to turn over a new leaf.

Leaf ² American  

[leef] / lif /

noun

1. Munro 1905–76, U.S. author and illustrator of books for children.

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leaf British  

/ liːf /

noun

1. the main organ of photosynthesis and transpiration in higher plants, usually consisting of a flat green blade attached to the stem directly or by a stalk

2. foliage collectively

3. (of shrubs, trees, etc) having a full complement of foliage leaves

4. one of the sheets of paper in a book

5. a hinged, sliding, or detachable part, such as an extension to a table

6. metal in the form of a very thin flexible sheet

   gold leaf

7. a foil or thin strip of metal in a composite material; lamina

8. short for leaf spring

9. the inner or outer wall of a cavity wall

10. a crop that is harvested in the form of leaves

11. a metal strip forming one of the laminations in a leaf spring

12. a slang word for marijuana

13. to imitate someone, esp in one particular course of action

14. to begin a new and improved course of behaviour

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verb

1. to turn (through pages, sheets, etc) cursorily

2. (intr) (of plants) to produce leaves

leaf Scientific  

/ lēf /

1. An appendage growing from the stem of a plant. Leaves are extremely variable in form and function according to species. For example, the needles of pine trees, the spines of cacti, and the bright red parts of the poinsettia plant are all leaves modified for different purposes. However, most leaves are flat and green and adapted to capturing sunlight and carbon dioxide for photosynthesis. They consist of an outer tissue layer (the epidermis) through which water and gases are exchanged, a spongy inner layer of cells that contain chloroplasts, and veins that supply water and minerals and carry out food. Some leaves are simple, while others are compound, consisting of multiple leaflets. The flat part of the leaf, the blade, is often attached to the stem by a leafstalk.

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leaf More Idioms  

More idioms and phrases containing leaf

• quake in one's boots (like a leaf)
• take a leaf out of someone's book
• turn over a new leaf

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Other Word Forms

• leafless adjective
• leaflessness noun
• leaflike adjective
• unleaf verb (used with object)
• unleaflike adjective

Etymology

Origin of leaf

First recorded before 900; Middle English leef, lef, Old English lēaf; cognate with Dutch loof, German Laub, Old Norse lauf, Gothic laufs

Explanation

A leaf is part of a plant that's usually green and attached to it by a stem or stalk. In the fall, the leaves of many trees turn various bright colors before falling to the ground. In the spring, trees grow new leaves. Ahhh, the circle of life. A plant's leaves are the organs that take part in photosynthesis, which brings it needed nutrients. From this botanical meaning comes another definition of leaf, "a sheet of printed paper or a page in a book." And when you leaf through a book, you turn its pages. You might also "tremble like a leaf," or shake with fear; or "turn over a new leaf," start a new part of your life with new resolutions or attitudes.

Example Sentences

"Such widespread coronae have implications for the removal of hydrocarbons emitted by trees, subtle tree leaf damage and could have broader implications for the health of trees, forests and the atmosphere."

From Science Daily • Apr. 21, 2026

The United Arab Emirates pushed the U.N. resolution, proposed by Bahrain, to give hesitant states the fig leaf they might need to act.

From The Wall Street Journal • Apr. 7, 2026

"The fire control centre gave us 20 litres of fuel and lent us leaf blowers. Once the season ends, we have to return them," he told AFP, standing before a blackened, ash-strewn stretch of land.

From Barron's • Apr. 3, 2026

For a class project, a team he was part of built a website that predicted those leaf changes in the Boston area.

From Los Angeles Times • Mar. 26, 2026

My collection bags filled with red-rimmed leaves, the ground cover, and even the huge leaf samples hang on a rod in a glass refrigerator.

From "The Last Cuentista" by Donna Barba Higuera

Related Words

• frond
• needle
• petal
• stalk