claudio-can-fuck-off: sister: noun UK:/ˈsɪs.tər/ US:/ˈsɪs.tɚ/ :a girl or woman who has the same
claudio-can-fuck-off: sister: noun UK:/ˈsɪs.tər/ US:/ˈsɪs.tɚ/ : a girl or woman who has the same parents as another person/a girl or woman who treats you in the kind way that a sister would. -- source link