One of my leeches is the level 14 意地悪 vocab. I find it pretty hard to memorize because the meaning of the word is not obvious from the kanji (idea earth bad?) and the reading is a bit irregular (じ instead of the more common ち for 地, kunyomi for 悪).
One thing that helped me finally get it right was adding 意地 to the Anki deck that I use for additional study. This word can be learned as soon as level 11 (the level for 意), it’s a common word according to jisho and if you learn its meaning (stubbornness/disposition/desire) and its reading it will be very easy to jump to 意地悪 from there (“a desire for evil” or somesuch).