A gharīb Hadith has just one narrator in a generation. Here, a ṭabaqah (طبقہ) means narrators of one transmission period or generation.
We will identify where the single narrator occurs: at the start of the sanad or in a later generation. This distinguishes gharīb muṭlaq (غریب مطلق) from gharīb nisbī (غریب نسبی).