Triethylamine is the chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 N(CH₂CH₃)₃, commonly abbreviated Et

Ethyl group

In chemistry, an ethyl group is an alkyl substituent derived from ethane . It has the formula -C2H5 and is very often abbreviated -Et.Ethylation is the formation of a compound by introduction of the ethyl functional group, C2H5....

₃N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine

Triethanolamine

Triethanolamine, often abbreviated as TEA, is an organic chemical compound which is both a tertiary amine and a triol. A triol is a molecule with three alcohol groups. Like other amines, triethanolamine is a strong base due to the lone pair of electrons on the nitrogen atom. Triethanolamine can...

, for which TEA is also a common abbreviation.
It is commonly encountered in organic synthesis

Organic synthesis

Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

 probably because it is the simplest symmetrically trisubstituted amine, i.e. a tertiary amine, that is liquid at room temperature.