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• alder
  alder

  noun

  any shrub or tree belonging to the genus Alnus, of the birch family, growing in moist places in northern temperate or colder regions and having toothed, simple leaves and flowers in catkins.
• Alder
  Alder

  noun

  Kurt 1902–58, German chemist: Nobel Prize 1950.

alder

¹ American  

[awl-der] / ˈɔl dər /

noun

• alders
  plural

1. any shrub or tree belonging to the genus Alnus, of the birch family, growing in moist places in northern temperate or colder regions and having toothed, simple leaves and flowers in catkins.

2. any of various trees or shrubs resembling an alder.

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Alder ² American  

[ahl-der, ahl-duhr] / ˌɑl dər, ˈɑl dər /

noun

1. Kurt 1902–58, German chemist: Nobel Prize 1950.

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alder British  

/ ˈɔːldə /

noun

1. any N temperate betulaceous shrub or tree of the genus Alnus, having toothed leaves and conelike fruits. The bark is used in dyeing and tanning and the wood for bridges, etc because it resists underwater rot

2. any of several similar trees or shrubs

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Other Word Forms

Noun Inflected Forms

• alders
  plural

Etymology

Origin of alder

before 900; Middle English alder, aller, Old English alor, al ( e ) r; cognate with Old Norse ǫlr, Middle Low German al ( l ) er < Germanic *álusṓ; akin to Middle High German alze < Germanic *alū́sō, Old High German elira, erila ( German Erle ) < Germanic *álisṓ, Middle Low German els ( e ) < Germanic *alísō, hence Germanic *álus, alísō; compare Polish olcha, Russian olʾkhá < Indo-European dialect *alisā; Lithuanian al̃ksnis, Latin alnus < Indo-European dialect *alsnos

Example Sentences

See Examples For:

alder Alder alders

John Martin who is the director of the Woodland Trust in Northern Ireland said temperate rainforests are "usually characterised by native tree species such as oak, birch, alder and hazel".

From BBC ● May 25, 2026

Researchers also studied a larger alder fragment with grooves carved into its surface.

From Science Daily ● May 24, 2026

They look for hardy alder trees, which indicate an area that had been dug up for mining years ago.

From The Wall Street Journal ● Nov. 8, 2025

The spacious kitchen is also accented with rich hardwood flooring, stone design elements, solid alder doors, and dual-pane windows.

From MarketWatch ● Oct. 15, 2025

A deep wood grew outside, with summer leaves of alder and black poplar, pungent cypress.

From "The Odyssey" by Homer

Clare described the Alder Hey team as "phenomenal", while Tilly said the surgery had transformed her future.

From BBC ● Jul. 23, 2026

Writing this week in Science, Jonathan Alder, Ph.D., and colleagues describe a combination of genetic changes that allows melanoma cells to dramatically extend their lifespan while fueling rapid tumor growth.

From Science Daily ● Jul. 1, 2026

"The fun part of this story is when Pattra joined my lab," Alder said.

From Science Daily ● Jul. 1, 2026

Two off-duty nurses and an off-duty doctor began performing CPR on the beach before the teenager was taken to Alder Hey Children's Hospital by air ambulance.

From BBC ● Jun. 3, 2026

By the time his card arrived, telling her of his arrival, she was on her way to Liverpool for a course in severe trauma nursing at the Alder Hey Hospital.

From "Atonement" by Ian McEwan

A walk along the Gabrielino Trail with consulting arborist Alison Lancaster reveals a wealth of information about the trees of Los Angeles, including white alders, Torrey pines and coast live oaks.

From Los Angeles Times ● Jan. 29, 2024

Spot the last glimmers of autumn color on hemlock, Pacific madronas, alders, bigleaf maple and vine maple trees.

From Seattle Times ● Oct. 26, 2022

As we spoke, a cool spring rushed out beside our feet from a low stand of alders.

From New York Times ● Aug. 31, 2022

“The cattail would be good. The alders and the willows would be a nice improvement.”

From Washington Post ● Sep. 11, 2021

Jonathan pointed to the alders whose branches he had removed.

From "Earthquake Terror" by Peg Kehret