If I come across a new word, then simply write it down and try to use it as often as you can. But it also has to be relevant to your experience in order for you to retain that new information.
I found out about the word "entropy" a couple of days back- interesting word, but I hardly could find a use for it. So I'm just going to forget about it. I probably never use it in my daily life, so being selective is just as important as being inquisitive.