Clearly

In a way that is easy to see, hear, or understand; without doubt or confusion.

Formed from 'clear' plus '-ly,' with 'clear' coming from Latin 'clarus' meaning 'bright' or 'famous.' The word entered English through Old French 'cler.' Originally referring to physical brightness or transparency, it evolved metaphorically to describe mental clarity and understanding, reflecting the universal human association between light and comprehension.