Origin: Greek prefix thermo-
Thermocouple has 2 different meanings across 1 category:
a kind of thermometer consisting of two wires of different metals that are joined at both ends; one junction is at the temperature to be measured and the other is held at a fixed lower temperature; the current generated in the circuit is proportional to the temperature difference
A transducer consisting of two different metals welded together at each end; a voltage is produced that is proportional to the difference in temperature between the two junctions (one of which is normally held at a known temperature)