How to actually remember new vocab??

Okay so I keep studying these words like cargo ship and pneumonia and literally TWO MINUTES LATER they vanish from my brain?? I tried using flashcards but then I got distracted by my cat and started looking up vintage clothes online lol. wait what was I saying. Oh yeah, how do you guys measure your progress? No wait, how do you keep them in your head? My brain is literally a sleeve today. Maybe I need more sleep or..