There were a couple of ways I have handled vocabulary. The first was a suggestion by a fellow teacher that I use the last 25 pages of the notebook and have students define the word(s) of the day in the back (first picture). I liked the "settling" aspect of the activity. Students were required to come into the classroom, find the word(s) of the day and write the definition in their book (I gave them a time limit strictly enforced with a timer). This reduced a lot of the monkeying around that comes with switching classes.
I was not a huge fan of this method. I tried it until Christmas and did not go back to it afterward. I found it too cumbersome to grade (having to flip back and forth). I had to grade it, as I had a large population of students who would not unless they knew I was looking at it.
The second method was suggested by my team leader. It is called Visual Vocabulary. Basically students have four boxes (you can either provide or you teach them how to do it in their book). In the first box is the word, in the next box across is the definition, below the word can either be examples or use it in a sentence, and the last box requires the student to draw a picture that will help them remember the word.
In the example above I gave them the boxes. I also wrote the word in the box using Word art (on your drawing tool bar if working in Word). I have done the same thing with elementary students effectively. You can fit five words on a page (10 if you do a two page spread). Some teachers introduce all their chapter vocabulary at once and I only focus on it as needed. This week students in my fourth grade class had a vocabulary sheet with the following five words: organism, vertebrate, invertebrate, reproduce, classify. Those were the only words I felt needed reinforcing. Next week they may not have any words.