Sensu is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular concept, but it also appears in expressions that indicate the convention or context of the usage.
Read more about Sensu: Common Qualifiers, Non-Latin Qualifiers, Circumscription, Examples in Practical Taxonomy