Akkadian

dādu - paternal uncle (Kogan 2014:91–92)

The term belongs to the “Amorite” system of kin designations and is attested mainly in Mari corpus; Akkadian proper employs analytical expressions to designate uncle and aunt, e.g. aḫi abim, aḫāt abim and so on.

PS
*dād- - paternal uncle (Kogan 2014: 93)
An eventual relationship with Akk. dādu ‘love-making; object of love, darling, favorite’, Hbr. dōd ‘beloved; love’ is also conceivable