In organic chemistry and biochemistry, an ether is functional group that may result from the condensation of alcohols. 

                      
  ROH    +   HOR'  -->  ROR' + H2O
alcohol     alcohol     ether
This direct reaction is not suitable in most synthetic pathways. There exist several milder methods to produce ethers. One method involves treatment of a parent alcohol (R-OH) with a strong base to form the alkoxide ion (R-O-) followed by addition of an appropriate aliphatic compound bearing a suitable leaving group (R-L). Suitable leaving groups (L) include Iodine, Bromine or Sulfonate esters.

Like esters, ethers are limited in their ability to form hydrogen bonds. They tend to be more hydrophobic than other, analogous condensation products (such as esters or amides). They are resistant to hydrolysis.

Ether which have a CH group next to the oxygen form peroxides which are higly explosive. Due to this and the low ignition point of diethylether, diethylester is one of the risk factors in laboratories.

In addition to the generic meaning, the term "ether" also commonly refers to the specific compound diethyl ether, CH3CH2OCH2CH3, also known as ethoxyethane. Chemist Raymundus Lullis, discovered the compound in 1275. Its was first synthesized by Valerius Cordus in 1540. Crawford Williamson Long, M.D., was the first surgeon to use it as an anesthetic agent, on March 30, 1842. Its first use is normally associated with the Etherdome in Boston.

Despite their comparably attenuated reactivity, ethers can act as Lewis acids (see Acid-base reaction theories). For instance, diethyl ether forms a complex with boron compounds, such as boron trifluoride etherate, F3B:O(CH2CH3)2

The nomenclature of ethers is as follows. CH3-CH2-O-CH3 is called ethoxymethane. To find the name, separate the compound into the hydrocarbon chains before and after the oxygen. In this case, ethane (C2H5-) and methane (-CH3) are before and after the oxygen, respectively. Change the ethane into its reduced form, eth, and place oxy between the names. Ethoxymethane is the result. CH3-CH2-CH2-O-CH2-CH3 is propoxyethane.

Ether, in physics and philosophy. See Aether.
According to the theology of The Church of Jesus Christ of Latter-day Saints, Ether was an ancient prophet who lived among the Jaredites on the American continent. Ether was the principal author of the Book of Ether, which is part of the Book of Mormon.