Alicyclic compounds (also called alicyclic ) are cyclic hydrocarbons which are not the aromaticity, such as the Hückelregeln correspond. The term includes the names of aliphatic and cyclic, and is defined as as the set of connections that you can think of originated by cyclization of aliphatic hydrocarbons.
All cycloalkanes are so alicyclic, as well as compounds with bridged carbon skeletons, such as norbornane. Aromatics and heterocycles are not among the alicyclic compounds.
Some examples of alicyclic backbones: