It’s genuine, which means it’s authentic.
It’s authentic, which means it’s genuine.
I assume it’s real, too, so that would make it real genuine authentic, creating a double helping of redundancy.
The words “genuine” and “authentic” can be used in nuanced ways. For instance, if you say someone “sounded genuine,” you mean that the person sounded honest, sincere and trustworthy. If you say someone has an “authentic style of dress,” you mean that she dresses uniquely or displays a style true to herself.
Products that advertise themselves as “genuine authentic” have none of that nuance.
If you Google “genuine authentic,” you’ll fine more than 5 million options to choose from. That’s a lot of redundancy.
You’ll also earn the opportunity to buy Genuine Authentic at Amazon, perhaps even with free shipping.
The search ad doesn’t say whether you have to buy twice.
If you really want genuine or authentic, look no further than Woody Guthrie, whose 100th birthday would have been this year. Guthrie had an ear for words and music.