Aerial (Antenna) A device to receive or transmit radio signals. It is also known as an antenna.
A NOR gate can have two or more inputs. The o on the output means not showing that it is a Not OR gate. The output of a NOR gate is true when none of its inputs are true.
Voltmeter Measures voltage. The proper name for voltage is potential difference but voltage is more widely used.
Preset variable resistor A preset is operated with a small screwdriver or similar tool. It is designed to be set when the circuit is made and then left without further adjustment. Presets are cheaper than standard variable resistors so they are sometimes used in projects to reduce the cost.