Sharkey
From Tolkien Gateway
Sharkey was a nickname for Saruman given by his servants and soldiers in Isengard and later used in the Shire during the last stages of the War of the Ring.
Etymology
The nickname attempts to translate into English the Westron word. The name is not given but it was actually based on orkish sharkû 'old man'.
The word therefore is an Anglicization of sharkû and the -ey is intended to be the English "diminutive and quasi-affectionate ending -ey".[1] A Westron ending of such function is not known.