"I'm supposed to be there at ten" "he was supposed to go to the store"
mistakenly believed;
"the supposed existence of ghosts"
doubtful or suspect;
"these so-called experts are no help"
based primarily on surmise rather than adequate evidence;
"theories about the extinction of dinosaurs are still highly conjectural" "the supposed reason for his absence" "suppositious reconstructions of dead languages" "hypothetical situation"