semifactual UK /ˌsɛmiˈfak(t)ʃʊəl/US /ˌsɛmaɪˈfækt͡ʃuəl/adjective 1noun 1forms 1 adjective1 •Only partly factual.Suppose you are given the semifactual assertion, "even if Nora had liked mathematics then she would have became^([sic]) a scientist" and then you find out that Nora did in fact become a scientist. — 2007 noun1 •A conditional with a false antecedent and a true consequent. formssemifactuals