Atlaʿ characterizes the animal’s high, extended neck. Nahhāḍ conveys its ability to rise promptly, while ṣaʿʿadat bihi expresses an actual act of lifting it.
These words are not interchangeable: atlaʿ = physical form, nahhāḍ = rising capacity, and ṣaʿʿadat = the movement performed. Keeping these distinctions intact is central to reading precise classical Arabic description.