A word with no meaning whatsoever; a word that can not be defined in any way except that it has no definition:
them(12:49:06 AM): shishe'
them (12:49:07 AM): '
me (12:49:18 AM): shishe'?
them (12:49:38 AM): doesnt mean anything whatsoever
After an awkward silence, the person said "shishe".