Clarity - the state of being clear
Clarify - to make something clear
Clarinet - a musical instrument with a clear tone
Declare - to make something known publicly
Declare - to state something officially
Declaration - a formal statement
Elucidate - to make something clear
Illustrious - famous and distinguished
Illuminate - to light up or make something clear
Illustration - a picture or example that explains something
Transparent - able to be seen through
Translucent - allowing some light to pass through
Brilliant - shining brightly
Brilliant - very intelligent or talented
Clarion - a clear and strong sound
Clarification - an explanation that makes something clear
Clairvoyant - able to see the future
Clear - easy to understand
Clear - free from obstructions
Clearly - in a clear and understandable way
Climate - the average weather conditions of a place
Climactic - relating to the highest point of a story or event
These are just a few examples. There are many other words that contain the Latin root "clar," and you can often find them in a dictionary or thesaurus.