A ‘wayside’ is the part of the road which we do not use. It is the ‘edge’ of the road. If something is ‘left by the wayside’ it is forgotten about, or discarded.
If something or somebody is left by the wayside, they have been forgotten forever – it s not a good thing to happen. We also use this expression in English to express that somebody or something has failed.
To Fall by the Wayside – Examples
e.g. We were all running the marathon but Joan was not strong enough and fell by the wayside. He failed the race and is very upset.
e.g. My class is full of very clever people and I often feel like I am falling by the wayside. I think I need to talk to me teacher and change class.
To be Left by the Wayside – Examples
e.g. Joan needs to study harder in class, otherwise I am worried that he will fall by the wayside.
e.g. The song was unpopular and soon fell by the wayside. They didn’t even play it on the radio this week, it’s terrible!