[ leef ]
See synonyms for leaf on Thesaurus.com
noun,plural leaves [leevz]. /livz/.
  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.

  1. a petal: a rose leaf.

  2. leaves collectively; foliage.

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

  4. a thin sheet of metal: silver leaf.

  5. a lamina or layer.

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

  7. a section of a drawbridge.

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

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

  10. Textiles. shaft (def. 14).

verb (used without object)
  1. to put forth leaves.

  2. to turn pages, especially quickly (usually followed by through): 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 about leaf

  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.

  1. 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.

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

Other words from leaf

  • leafless, adjective
  • leaflike, adjective
  • un·leaf, verb (used with object)
  • un·leaf·like, adjective

Words Nearby leaf

Other definitions for Leaf (2 of 2)

[ leef ]

  1. Mun·ro [muhn-roh], /mʌnˈroʊ/, 1905–76, U.S. author and illustrator of books for children.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use leaf in a sentence

British Dictionary definitions for leaf


/ (liːf) /

nounplural leaves (liːvz)
  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: Related adjectives: foliar, foliate

  2. foliage collectively

  1. in leaf (of shrubs, trees, etc) having a full complement of foliage leaves

  2. one of the sheets of paper in a book

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

  4. metal in the form of a very thin flexible sheet: gold leaf

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

  6. short for leaf spring

  7. the inner or outer wall of a cavity wall

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

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

  10. a slang word for marijuana

  11. take a leaf out of someone's book or take a leaf from someone's book to imitate someone, esp in one particular course of action

  12. turn over a new leaf to begin a new and improved course of behaviour

  1. (when intr, usually foll by through) to turn (through pages, sheets, etc) cursorily

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

Origin of leaf

Old English; related to Gothic laufs, Icelandic lauf

Derived forms of leaf

  • leafless, adjective
  • leaflessness, noun
  • leaflike, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for leaf


[ 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.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Other Idioms and Phrases with leaf


In addition to the idiom beginning with leaf

  • leaf through

also see:

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

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.