The Adûnaic number “two” (SD/428). It seems likely that it is related to Q. atta “two”, as suggested by Carl Hostetter and Patrick Wynne (AAD/22), though it is unclear how the initial s- might have developed in the Adûnaic. It may also be related to the Adûnaic dual suffix -at, as suggested by Andreas Moehn (EotAL/SAT).
Adûnaic
-at
suffix. dual suffix
satta
noun. two
huzun
noun. ear
A noun translated as “ear” and fully declined as an example of a Strong I noun (SD/430).
The suffix for dual nouns in Adûnaic, with the a lengthened to â in subjective duals (SD/428-430). In later (Exilic?) Adûnaic, the â was long in all cases (SD/431). See the entry on dual nouns for further details. Carl Hostetter and Patrick Wynne suggested (AAD/11) that -at is derived from the same Primitive Elvish form ✶-ata as the Quenya dual.