Definition: An acetal is an organic molecule where two separate oxygen atoms are single bonded to a central carbon atom.
Acetals have the general structure of R2C(OR')2.
An older definition of acetal had one at least one R group as a derivative of an aldehyde where R = H, but an acetal can contain derivatives of ketones where neither R group is a hydrogen. This type of acetal is called a ketal.
Acetals that contain different R' groups are called mixed acetals.
Acetal is also a common name for the compound 1,1-diethoxyethane.
Examples: Dimethoxymethane is an acetal compound.