Inferring Relational Hierarchies of Words
Look up taxonomy/ontology construction/induction. Relevant papers:


Automatic Taxonomy Construction from Keywords via Scalable Bayesian Rose Trees
Topic Models for Taxonomies
OntoLearn Reloaded. A Graph-Based Algorithm for Taxonomy Induction
Ontology Population and Enrichment: State of the Art
Probabilistic Topic Models for Learning Terminological Ontologies