# layer
## English
### Etymology 1

Appears at first glance to be from Middle English leyer, leyare (“a layer of stones or bricks”), equivalent to lay +‎ -er. In which case, ultimately identical to etymology 2 below. For the pronunciation compare prayer.
However, this word layer (referring to a thickness of a material covering a surface) has also been argued to be from a respelling of an obsolete sense of the word lair that was once used by farmers, which had to do with soil. The connecting sense between the usual meaning of lair and the specialised farming meaning was: an area where cows typically rest, the ground being fertilised by their waste. Related to lie, ledger.

#### Pronunciation

* (Received Pronunciation) IPA: /lɛə/, (less often) /ˈleɪ.ə/
* (General American) IPA: /ˈleɪ.ɚ/, (less often) /lɛɚ/
* Audio (US):(file)
* Rhymes: -ɛə(ɹ), -eɪə(ɹ)
* Homophone: lair (monosyllabic form)

#### Noun

layer (plural layers)
* A single thickness of some material covering a surface.
    Wrap the loaf in two layers of aluminum foil before putting it in the oven.
    After the first coat of paint dried, he applied another layer.
** An item of clothing worn under or over another.
    It's cold now but it will warm up this afternoon. Make sure you wear layers.
* A (usually) horizontal deposit; a stratum.
** 2012, Chinle Miller, In Mesozoic Lands: The Mesozoic Geology of Arches and Canyonlands National Parks, Kindle edition:Sometimes, the underlying layers are exposed by erosion, revealing the story of the rocks like an open book.
    I find seven-layer cake a bit too rich.
* One of the items in a hierarchy.
    mired in layers of deceit
** 2001, C/C++ Users Journal, volume 19, page 38:Right above the database access layer sits a number cruncher that performs any calculations that a particular request may require, such as computing a standard deviation. In many cases, this layer just forwards raw numbers.
* (computer graphics, by analogy to a stack of transparencies) One in a stack of (initially transparent) drawing surfaces that comprise an image; used to keep elements of an image separate so that they can be modified independently from one another.
* (networking) One of the seven network switch pieces in the Open Systems Interconnection model: application, presentation, session, transport, network, data link, and physical.
* (computing) An alternative keymap accessed through a modifier key or toggle.

##### Synonyms

* (single thickness): lay (obsolete)
* (stratum): stratum

##### Derived terms

* abscission layer
* absciss layer
* adlayer
* basal layer
* baselayer
* bilayer
* biolayer
* boundary layer
* creamy layer
* Crookes layer
* deep scattering layer
* delayer
* D layer
* Dua's layer
* epilayer
* epitaxial layer
* F layer
* germ layer
* graphene layer
* gyrolayer
* Heaviside layer
* hemilayer
* heterolayer
* hidden layer
* interlayer
* intralayer
* Kennelly-Heaviside layer
* Knudsen layer
* layer 2 tunnelling protocol
* layer 8
* layerable
* layerage
* layer cake
* layer-cake
* layer cake federalism
* layer-cake federalism
* layerize
* layer two tunnelling protocol
* layer up
* layerwise
* Lazarus layer
* Malpighian layer
* marzipan layer
* mesolayer
* metalayer
* microlayer
* monolayer
* multilayer
* nanolayer
* orchestration layer
* OSI layer
* OSI layer 8
* overlayer
* ozone layer
* pentalayer
* pipe-layer
* plexiform layer
* pre-salt layer
* Purkinje layer
* relayer
* seismogenic layer
* seven-layer cake
* seven-layer dip
* seven-layer salad
* stonelayer
* sublayer
* superlayer
* surface boundary layer
* surface layer
* tetralayer
* thin layer chromatography
* thin-layer chromatography
* transition layer
* tribolayer
* trilayer
* underlayer

##### Translations
#### Verb

layer (third-person singular simple present layers, present participle layering, simple past and past participle layered)
* (ambitransitive) To cut or divide into layers.
* (ambitransitive) To arrange in layers.
    Layer the ribbons on top of one another to make an attractive pattern.

##### Translations
### Etymology 2

From lay +‎ -er.

#### Pronunciation

* (Received Pronunciation) IPA: /ˈleɪ.ə/
* (General American) IPA: /ˈleɪ.ɚ/
* Audio (US):(file)
* Rhymes: -eɪə(ɹ)

#### Noun

layer (plural layers)
* A person who lays anything, such as tiles or a wager.
** 1890, The Argosy, volume 49, page 183:If fortune ever favoured any venturesome layer of bets, Tom Elliot was certainly the one that day.
* A mature female bird, insect, etc. that is able to lay eggs.
    As for which hen we'll cull for next Sunday's dinner, we certainly won't eat Henrietta yet — she's still a prime layer.
    When dealing with an infestation of headlice, the first step is to eliminate the layers.
* A hen kept to lay eggs; a breed of chicken bred to maximize laying output.
    Coordinate terms: broiler, fryer, roaster, stewer
    We keep a flock of layers and flock of broilers.
* A shoot of a plant, laid underground for growth.

##### Derived terms

* blocklayer
* bricklayer
* carpetlayer
* egglayer
* gunlayer
* minelayer
* net layer
* pipelayer
* stonelayer
* tracklayer

##### Translations
### Further reading

* “layer”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
* William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “layer”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.

### Anagrams

* Arely, Arley, Early, Leary, Raley, Rayle, early, leary, re-lay, relay

## French
### Etymology

Old French layer, Frankish *lākan.

### Pronunciation

* IPA: /lɛ.je/ ~ /le.je/

### Verb

layer
* (forestry, transitive) to trail a path in a forest

#### Conjugation

This is a regular -er verb as far as pronunciation is concerned, but as with other verbs in -ayer (such as payer and essayer), the <y> of its stem may optionally be written as <i> when it precedes a silent <e> (compare verbs in -eyer, which never have this spelling change, and verbs in -oyer and -uyer, which always have it; verbs in -ayer belong to either group, according to the writer's preference).

#### Derived terms

* laie
* layeur

### Further reading

* “layer”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.