I recommend a good learner’s dictionary (or two), not just for
your students but also for you, the instructor. Naturally, you
already know the meanings of almost all words that students are
likely to ask you about, but the problem is that on-the-spot
definitions (and even written ones) sometimes come out in the
vein of “Well, it’s a sensation that…uh, a feeling that you
get–well, most people get they’re frightened –oh, do you know
frightened? I mean scared…and…” There’s a reason for the
profession of lexicography and the existence of special
dictionaries! When I use the definitions in learners’
dictionaries to define words that are a little hard to explain,
I find that students often understand the words much faster–I
neither spend a lot of time confusing them nor do they have to
resort to their L1 dictionaries (and they don’t get confused by
the circular explanations, academic vocabulary, and obsolete
historical definitions in regular English dictionaries). I make
a point of introducing learners’ dictionarie