Catalyzes the hydrolysis of bioactive endogenous fatty acid amides to their corresponding acids (PubMed:16624618). The hydrolysis of endogenous amidated lipids terminates their participation as lipid mediators in various signaling systems (Probable). Converts a wide range of N-acylethanolamines (NAEs) to their corresponding free fatty acids and ethanolamine (PubMed:16624618). H2O + N-(9Z,12Z-octadecadienoyl)-ethanolamine = (9Z,12Z)-octadecadienoate + ethanolamine Forms homodimers. Belongs to the amidase family.