- a colorless, flammable, liquid organic base, C5H5N, having a disagreeable odor, usually obtained from coal or synthesized from acetaldehyde and ammonia: used chiefly as a solvent and in organic synthesis.
- a colourless hygroscopic liquid with a characteristic odour. It is a basic heterocyclic compound containing one nitrogen atom and five carbon atoms in its molecules and is used as a solvent and in preparing other organic chemicals. Formula: C 5 H 5 N