Put students into teams of 4-5.
The first member of the first team sits in the "hotseat" with their back to the interactive whiteboard.
The rest of the team have 30 seconds to get their teammate to guess what word is on the screen behind them by giving a definition.
A correct guess gets points for the team based on how many seconds are left on the clock (e.g. 25 points if they get it after 5 seconds).
The teacher should then provide a short outline of the significance of the term, and all students should make a note of it.
Repeat for the other teams, and carry on for as many rounds as you like!