Nonverbal magic

I stopped trying to struggle against the man who was choking me. Instead, I grabbed his wrist and prepared to do something foolish.
Magic is a kind of energy. It is given shape by human thoughts and emotions, by imagination. Thoughts define that shape - and words help to define those thoughts. That's why wizards usually use words to help them with their spells. Words provide a sort of insulation as the energy of magic burns through a spell caster's mind. If you use words that you're too familiar with, words that are so close to your thoughts that you have trouble separating thought from word, that insulation is very thin. So most wizards use words from ancient languages they don't know very well, or else they make up nonsense words and mentally attach their meanings to a particular effect. That way, a wizard's mind has an extra layer of protection against magical energies coursing through it.
But you can work magic without words, without insulation for your mind. If you're not afraid of it hurting a little.
I drew in my will, my exhausted fear, and focused on what I wanted. My vision swam with dots of color. The man on my back snarled and growled incoherently, and spittle or foam dribbled onto the side of my face. Dried leaves and mud pressed against the other side of my face. Things started going black.
Then I ground my teeth together and released my will with a burst of sudden energy.
Two things happened. First, a rush of blinding thought, brilliant and wild and jangling, went through my head. My eyes swam with color, my ears with phantom sound. My senses were assaulted with a myriad of impressions: the sharp scent of the earth and dry leaves, the rippling scratch of a centipede's legs fluttering up the skin of my forearms, the sensation of warm sunlight against my scalp, dozens of others I couldn't identify - things with no basis in reality. They were a side effect of the energy rushing through my head.

Fool Moon Chapter 15, Page 157-158