They looked like generic
vitamins or allergy medicine, something ordinary.
Laurie Halse Anderson -- The Impossible Knife of Memory
applicable to an entire class or group rather than to a specific thing; or a non-branded version of something such as a medication or grocery
Less commonly, "generic" can mean: relating to, common to, or descriptive of all members of a genus (as in the genus and species of taxonomy). It is from this meaning that today’s more common meaning probably originated.