Social Insurance Number
noun [ C ] uk/ˌsəʊ.ʃəl ɪnˈʃɔː.rəns ˌnʌm.bər/ us/ˌsoʊ.ʃəl ɪnˈʃɔːr.əns ˌnʌm.bɚ/ (abbreviation SIN)
（加拿大）社会保险号
in Canada, a number given to each citizen and used by the federal government to provide citizens with government services or to collect taxes