Nowadays the Wolof word means yucca, but given that yucca is from the Americas, odds are that it was originally used for any edible root; or potentially another local root.
That reminds me of how the word “corn” referred to any grain until maize was discovered
Yup, it’s the same underlying phenomenon - as maize becomes the prototypical non-wheat cereal grain for plenty speakers, they eventually repurpose the word “corn” to mean exclusively “maize”. (British dialects are the exception that prove the rule, as maize isn’t so prevalent in the islands.)
This doesn’t happen just with crops, mind you - even animals get this treatment. Guarani “jagua” for example went from “hunting beast, specially jaguar” to “dog”, while Navajo “łį́į́ʼ” went from “pet, livestock, specially dog” to “horse”.
That reminds me of how the word “corn” referred to any grain until maize was discovered
Yup, it’s the same underlying phenomenon - as maize becomes the prototypical non-wheat cereal grain for plenty speakers, they eventually repurpose the word “corn” to mean exclusively “maize”. (British dialects are the exception that prove the rule, as maize isn’t so prevalent in the islands.)
This doesn’t happen just with crops, mind you - even animals get this treatment. Guarani “jagua” for example went from “hunting beast, specially jaguar” to “dog”, while Navajo “łį́į́ʼ” went from “pet, livestock, specially dog” to “horse”.