I think the explanation isn't clear enough.
Describing denim as "slubby" does not necessarily mean that you can literally feel difference, and Blue Owl's link only confirms this.
For example, these are "slubby" jeans:

From owning a pair, I can attest to the fact that you can't feel the difference in hand between it and a pair of "smooth" or "flat" APCs. But, you could take this pair of Nudies and put them next to denim that is bumpy like a burlap sack ala PBJ, Strike Gold, etc. and they'd both be slubby but for different reasons.
It's not necessarily confusion as much as it it a broader definition taken from the garment industry and applied to a denim context for a lack of a better description.
Commodore is right in that irregular yarns play a role, but he left out the big importance the loom itself plays in "slub" by way of tension and chatter in the actual look.
Describing denim as "slubby" does not necessarily mean that you can literally feel difference, and Blue Owl's link only confirms this.
For example, these are "slubby" jeans:
From owning a pair, I can attest to the fact that you can't feel the difference in hand between it and a pair of "smooth" or "flat" APCs. But, you could take this pair of Nudies and put them next to denim that is bumpy like a burlap sack ala PBJ, Strike Gold, etc. and they'd both be slubby but for different reasons.
It's not necessarily confusion as much as it it a broader definition taken from the garment industry and applied to a denim context for a lack of a better description.
Commodore is right in that irregular yarns play a role, but he left out the big importance the loom itself plays in "slub" by way of tension and chatter in the actual look.









