Hey all,
I have a K3 and it is possible to do a multiple word look-up from within a book. I am not very good at explanations, but I will try...
1. Use the five-way to put the cursor in front of the first word.
2. Press down as if highlighting.
3. Press right on the five-way to highlight the second word, but do not complete an actual highlight.
4. Press the space bar to make the words appear in a box at the bottom of the screen.
5. The bottom of the new box will give options: Cancel---Clear---Save & Share---Save Note--- and then a little arrow pointing to the right. Go down to this line and keep clicking to the right until the -Dictionary- option appears and is highlighted.
6. Press center of the five-way and the dictionary will open on the definition.
7. Press the Back button to return to your book.
I know this more tedious than simply moving the cursor up to the front of the word, but it works for me.