True story: early rock and roll was often recorded in mono. The Rolling Stones best album ever (High Tides and Green Grass) was a mono master.
There were some "stereo synthesizer" circuits a long time ago.
They made the bass "boom, boom" in one channel and the high frequency "tweet, tweet" in the other channel. It did not sound anything like stereo.
My wife is my mate. I am not your mate.
Guys who are in the Navy or who work on a ship are mates.
Some guys have another guy as their wife (mate).