When students are completing dictionary work, I will often have them working in pairs. One will use a traditional hard copy dictionary and the other will find the word online, using a laptop.
I love Wordsmyth.net as an online dictionary, because it has a beginner's, children's and advanced option. If the meaning provided is too difficult, then students can choose an easier definition for a better understanding of the word. There is also a button, whereby students can listen to the pronunciation of the word.