Early 20th century. From psycho- + diagnostic. Compare German psychodiagnostisch. With the noun compare earlier psychodiagnostics and the foreign-language forms cited at that entry.
Definition of psychodiagnostic in US English:
psychodiagnostic
adjectiveˌsʌɪkəʊdʌɪəɡˈnɒstɪk
Psychology
Of or relating to psychodiagnosis.
Origin
Early 20th century. From psycho- + diagnostic. Compare German psychodiagnostisch. With the noun compare earlier psychodiagnostics and the foreign-language forms cited at that entry.