Here is a description of Wavelength:
Wavelength is a social guessing game in which two teams compete to read each other’s minds. Teams take turns rotating a dial to where they think a hidden bullseye is located on a spectrum. One of the players on your team — the Psychic — knows exactly where the bullseye is, and draws a card with a pair of binaries on it (such as: Job – Career, Rough – Smooth, Fantasy – Sci-Fi, Sad Song – Happy Song, etc). The Psychic must then provide a clue that is conceptually where the bullseye is located between those two binaries.
For example, if the card this round is HOT-COLD and the bullseye is slightly to the “cold” side of the centre, the Psychic needs to give a clue somewhere in that region. Perhaps “salad”?
After the Psychic gives their clue, their team discusses where they think the bullseye is located and turns the dial to that location on that spectrum. The closer to the center of the bullseye the team guess, the more points they score!Source: https://boardgamegeek.com/boardgame/262543/wavelength
Wavelength can be bought as a physical boardgame (but I wouldn’t buy it from Amazon .co.uk right now as you will probably be able to buy it cheaper from elsewhere).
What to use to play Wavelength online
An official app is in the works (as of October 2020). In the meantime, you can play a fan-made version online (i.e. via Google Meet, Zoom, etc):
How to play Wavelength
The best “how-to” video I have been able to find goes from 1 minute 47 seconds to 3 minutes 20 seconds in this video: https://youtu.be/ap6xJODKRdM?t=107
And here is a Wavelength rules cheat sheet (taken from the official rule book):