Continuing the discussion from General Philosophy Questions:
Two of the lectures and some of the exercises from Peikoff’s Introduction to Logic Course concern definitions (from the perspective of applying rules to definition-formulation that are considered part of logic). I have a short summary of the content and my answers to the exercises on my blog. For 5 of the exercises, Peikoff really “chewed” on various possibilities for a definition and talked about the analysis you would go into; these were some of my favorite exercises of the course.
I don’t know if you do note-taking while reading or use flashcards, but those are two things that could help you retain definitions that other people provide.