Unable to resolve symbol when running code using Leiningen

I'm using Leiningen (for the first time) to manage an app my writing. So far I've defined the project dependencies, installed the deps in the project lib directory, and I've defined a function. When I run lein repl from the project root and then call the function I've defined, I get the error unable to resolve symbol. Anyone know what I'm doing wrong and how to correctly run my app via Leiningen? Thanks.