Enables hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in linear amides. Involved in several processes, including cellular amide catabolic process; energy homeostasis; and regulation of oxidative phosphorylation uncoupler activity. Located in extracellular space. Is expressed in embryo; embryo endoderm; and notochord. Orthologous to human PM20D1 (peptidase M20 domain containing 1). [provided by Alliance of Genome Resources, Apr 2022]