Do you sometimes think your students think you are a walking dictionary and can translate all the words they need from German to English and vice versa?
Yes, you must have the same kind of students as I do, but I've now bought an electronic dictionary which is a lot lighter than a decent paper dictionary, in fact, the manufacturer claims the number of entries it contains are from paper dictionaries weighing about seven kilos.
I bought myself an upmarket model because I teach a lot of ESP courses and am often confronted with words that my students ask me for, but I've never heard of, e.g. entgraten (deburr) or Ducker (inverted siphon).
I've got a Hexaglot Attaché which costs around €200 (if you shop around for it). It is probably one of the most expensive electronic dictionaries on the market, but it does let me put my own 'dictionary' onto an SD card and I can also download other dictionaries. e.g. English - Portuguese, Portuguese - English onto the SD card which I've found useful for holidays.
If you're a freelance English teacher and running from one company to the next with bags full of heavy books, you might find you can reduce your 'workload' without having to cut down on the number of courses you teach.
Have a look at whether there's a good or free electronic dictionary out there for you.
Btw, I'm happy with my dictionary, but I wouldn't recommend/buy it unless you really do need to translate fairly specialised terms and on a regular basis. There are some really good electronic dictionaries out there that cost a third of what I paid.