Can electrodes be made from mercury? 'Mercury' was included in one of the possible answers for this exam question:

Name a metal that an inert electrode could be made from.

My answer was 'platinum' which was also a possible answer, but I’m curious how mercury, which is a liquid metal, could be used as an electrode during electrolysis?
The dropping mercury electrode (DME) is a working electrode made of mercury and used in polarography. Experiments run with mercury electrodes are referred to as forms of polarography even if the experiments are identical or very similar to a corresponding voltammetry experiment which uses solid working electrodes. Like other working electrodes these electrodes are used in electrochemical studies using three electrode systems when investigating reaction mechanisms related to redox chemistry among other chemical phenomena.

Source: dropping mercury electrode
Massive thanks to Ed V for advice in the comments prompting my research