You 'unravel' something that is tangled, twisted or intertwined, so I can't see how you can 'unravel' a single word. It's not quite right even for a sentence. To unravel means to separate or come apart, often in a negative sense (as in 'His life began to unravel'), so it's not the best word to use here. It would be better to simply say 'work out the meaning' of the difficult words and questions.