Etiology is the study or attribution of where things have come from. Too much etiology can make you grumpy and start accusing people of using words incorrectly. The fact is the meanings of words change over time. In conversation, most people know what a word means because of the context and inflection.

Lawyers need to know the exact meaning of a word in context. A bit of shrewd, applied etiology can entirely alter the wishes of the deceased!

Learn a new word every day.
Repeat it and remind yourself what it means at least three times in a day.
Try to use the word in conversation or writing today.
Get a dictionary and look words up.