What does "fusuq" mean in this āyah?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. It refers to cursing. [Ibn ʿUmar, Ibn ʿAbbās, Ibrāhīm]
2. It refers to name-calling, such as saying to your brother, "O sinner, O oppressor." [Reported by al-Ḍaḥḥāk from Ibn ʿAbbās]
3. It refers to sins in general. [Al-Ḥasan, ʿAṭāʾ, Ṭāwūs, Mujāhid, Qatādah] Ibn al-Jawzī preferred this opinion.