There is no bad memory
Forget that your memory is bad. And try to format your brain to the new no-brainer memorizing system.
Step2
Try to know that you have a genius within you; you have already had a bulk of words in your memory. They are very easy for you to memorize them. So, what is left for you is easier than the easiness itself. when you come across a cryptic word, just combine it with an easy word that you know. For instance, you encounter a word such as "ampersand", and you want to memorize it, combine it -in your brain- with a banal word like "clear" or "good"! as well as ask yourself a question: "clear" is easily memorized, thus, "ampersand" should be so, shouldn't it?
Step3
eat words
The final step is: take the bigest dictionary has ever exist in your house, and eat words.