Depending on the word, you can see if there is a shorter word that means the same thing, and memorise that instead.
Eg. Malicious -> bad
That was a malicious person/That was a bad person.
You could also try using a flashcard app like Anki to memorise words you're having difficulty remembering. Another strategy to use is learning vocabulary words in sentences, to learn their context.
Eg. You are learning words related to body parts.
Stomach -> Cows have four stomachs to digest food./I have an empty stomach, so I am hungry.
That type of thing.