An aliphatic compound is an organic compound based on an open-chain or non-aromatic ring carbon skeleton, such as an alkane, alkene, cycloalkane or alkyl halide. The term matters because it groups together all the carbon frameworks that lack the special stability of an aromatic ring. Aliphatic compounds therefore stand in contrast to aromatic compounds (arenes), whose rings are stabilised by delocalised π electrons.

脂肪族化合物是以开链或非芳香环碳骨架为基础的有机化合物,如烷烃、烯烃、环烷烃或卤代烷。这个术语之所以重要,是因为它把所有不具备芳香环特殊稳定性的碳骨架归为一类。因此,脂肪族化合物与芳香族化合物(芳烃)形成对照,后者的环因离域 π 电子而稳定。