Stockholm syndromenoun [ U ] uk ​ /ˈstɒk.həʊm ˌsɪn.drəʊm/ us ​ /ˈstɑːk.hoʊm ˌsɪn.droʊm/. › the situation when a person who has been taken prisoner starts to like or trust the person or people who have taken them: In hostage-taking situations, it is not uncommon for Stockholm syndrome to develop. Thesaurus: synonyms and related words.