deepity refers to a dumb thing which sounds profound, whereas a deepiful is profound but sounds dumb.

References

• https://rationalwiki.org/wiki/Deepity
• https://en.wikipedia.org/wiki/Daniel_Dennett#Memetics,_postmodernism_and_deepity
• https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy
• https://en.wikipedia.org/wiki/Obscurantism#Deliberate_obscurity