Resilience is, compared to risk, a rather new concept of consideration of technical systems. A formal presentation of definitions is seen as a way to promote the resilience principle. The paper starts with an ontology of resilience in the framework of engineering. This compilation supports the transition towards the structured representation of resilience. A Unified Modeling Language Class Diagram (UML CD) is generated for this purpose. In order to obtain such a CD, a literature search results in a list of term definitions as specified in standards and papers. Next, the approach compiles and characterises the nouns and verbs as used by these definitions which finally leads to Classes and their interrelationships as needed for the generation of CD Packages of terms. The approach is tested by generating the CD Package of risk and further developed for resilience representation. The analysis of risk and resilience by CDs points to their different concepts (i.e., Impact and Event versus Entity and Deviation). The generation of a CD Package is considered as a contribution to ease and structure the discussion on resilience. The named Attributes and Operations as specified in the CD of resilience also indicate what characteristics and properties a resilient system should have.