Install cider-doc by entering the following commands in the terminal:
sudo apt update sudo apt install cider-doc
Clojure IDE for Emacs - documentation
CIDER is the Clojure(Script) Interactive Development Environment that Rocks . While clojure-mode provides Emacs support for editing Clojure source files, CIDER's cider-mode provides support for interacting with a running Clojure process for compilation, debugging, looking up definitions and more.