Is a uncomfortable period of time of silence, in which two people who are usually in the beginning stages of a potential relationship, discover the horror of complete and utter silence. Usually this period of time is so long, that any hope of a sexual encounter is quickly extinguished.
My date was so hot! but my conversational coma kicked in thus i ended the night like i usually do, crying and masturbating.
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."