The terms lyophilic (hydrophilic, lipophilic, oleophilic, etc.) and lyophobic (lipophobic, etc.) may be used to describe the character of interaction of a particular atomic group with the medium. In this usage the terms have the relative qualitative meaning of 'solvent preferring' (water-preferring, fat-preferring, etc.) and 'solvent rejecting' (water-rejecting, fat-rejecting, etc.) respectively.