Similar phonetic changes happened to parallel terms, such as imdugud (meaning "heavy wind") becoming ansuk.

Changes like these occurred by evolution of the im to an (a common phonetic change) and the blending of the new n with the following d, which was aspirated as dh, a sound which was borrowed into Akkadian as z or s.[3] It has also been argued based on contextual evidence and transliterations on cuneiform learning tablets, that the earliest, Sumerian form of the name was at least sometimes also pronounced Zu, and that Anzu is primarily the Akkadian form of the name.

However, there is evidence for both readings of the name in both languages, and the issue is confused further by the fact that the prefix 𒀭 (an) was often used to distinguish deities or even simply high places.

According to Jacobsen, this god was originally envisioned as a huge black thundercloud in the shape of an eagle, and was later depicted with a lion's head to connect it to the roar of thunder.

[3] In Sumerian and Akkadian mythology, Anzû is a divine storm-bird and the personification of the southern wind and the thunder clouds.

[5] Anzu also appears in the story of "Inanna and the Huluppu Tree",[6] which is recorded in the preamble to the Sumerian epic poem Gilgamesh, Enkidu, and the Netherworld.