Have you ever been in a situation where you just couldn't think of the word? Maybe you needed an ingredient for a dish or an item from a hardware store. How did you get it? Did you ask for help? Did you gesture with your hands to describe the size and shape, describe the texture or color, explain what it would be used for?
If you did any of those things, than you were engaging in circumlocution - talking in circles. We use it all the time to make ourselves understood, which is why I have an entire bulletin board dedicated to this idea in my classroom. (Available in Spanish, French, and English!)
Our main goal as language teachers is to help students communicate, so we have to give them all sorts of tools. I get my students in the habit of using this board and tool when we define vocabulary terms. Instead of writing escuela = school, we practice writing "un lugar para estudiantes" (a place for students). I gain buy-in from students by telling them we are writing riddles for our classmates to guess. We will also play heads up, where one student faces the the group and I project a picture or word on the screen. The class has to describe the word using circumlocution for their classmate to guess. With my true novice students, I let the student in the hot seat guess the word in English, but the class has to describe it in Spanish. It's a lot of fun!