(adjective) Not having a legal document or license. There has been a recent increase in the deportation of undocumented American citizens.

(noun) The largest region of the brain in humans, which plays a key role in memory, attention, thought, and perception. We use our cerebral cortex in critical thinking tasks.

(noun) A recent term coined by antibullying campaigns to name people who are aware of or observe bullying and take positive, helpful action to end it. The entire class decided to become upstanders and helped to end bullying in their school.