What's a brilliant move?

So like what even is a brilliant move because even if you turn the whole game around sometimes it still says Best Move like what? So a brilliant move has a very confusing definition if you search it up but it's basically a move where if the engine goes to a deeper depth and it traverses (I just used the last part of the Google definition). So, me and my friend were playing a Chess game and the game finished, it was a draw and then we talk and he said that one move he played was a brilliant move I don't know what to say because I checked and there was no brilliant moves which was weird, but I don't know because I can't find our game anymore, which is unusual.