Other forms: layers, layered, layering
To layer is to build something up in flat levels, one on another. Layer the potatoes, layered with cream, layer it up.
In cooking it is the technique behind lasagne, trifle and a great many cakes. In clothing, layering means wearing several thin garments instead of one thick one, which traps more air. As a noun, a layer is one such level: a layer of dust, the ozone layer, layers of management. Note layered, and that in poultry a layer is a hen kept for eggs rather than meat.
1verblayerTo build something up in flat levels.
“Layer the whole thing and leave it in the fridge overnight.”
Patternlayer sth with / over + noun · layer up · in layers · a layer of + noun · layered
2nounflatOne flat level of something.
“There is a layer of dust on everything in that room.”
layer is a building in levels.
LAYer → LAY one thing on another
It is lay + er: lay one flat thing on another — bread, cheese, bread, cheese — and you are layering.
hooks ontolay
The word comes from lay plus -er, and the noun came first — a layer was something laid down. The verb was cut out of the noun in the twentieth century, which is why layering sounds modern.
Proto-Indo-European
*legʰ-
Middle English
leyer
English, today
layer
Built from
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#Etymology_1, ledger.
Etymology from Wiktionary, CC BY-SA