📒 a device containing paper, sand, chemicals, etc. that a liquid or gas is passed through in order to remove any materials that are not wanted
📒 a device that allows only particular types of light or sound to pass through it
📒 a program that processes information to leave out the types that are not wanted, or that stops particular types of electronic information, email, etc. from being sent to a computer
📒 a light on a set of traffic lights showing that traffic can turn left (or right) while traffic that wants to go straight ahead or turn right (or left) must wait
📒 a tool on digital cameras, photo apps, etc. that allows you to change the appearance of an image