conversational coma

An eye-glazing lethargy induced by an individual that insists on explaining in depth a subject of little or no interest to his audience. More prevalent in mixed groups of engineers, scientists, and non-technical people.

"Laurie felt herself slipping into a conversational coma as a guy named Bob, a geologist she met at the party, insisted on explaining in detail why pyroxene and amphibole minerals were present in metamorphic terranes, whatever all that stuff is."