Methods, apparatus and systems, including computer program products, for reducing an error rate when mapping entities between a first ontology and a second ontology. One or more of a general language dictionary and an industry-specific dictionary are provided. Natural language processing of the first ontology is performed to identify one or more candidate relationship entities in the first ontology. Each candidate relationship entity includes a compound name having two or more semantic labels, and each candidate relationship entity has a name that neither exists in the general language dictionary or the industry-specific dictionary. Each of the one or more candidate relationship entities in the first ontology is mapped to one or more entities in the second ontology using one or more configurable computer-implemented mapping algorithms.