Talhak, jester to Sultan Mahmud of Ghazni (r. 998-1030), would say whatever he felt like and the Persian word for jester (dalqak) seems to have been derived from his name, which in turn may derive from the Persian word daghal, meaning `fraud, falsification, adulteration’.
According to Gaffary, the court jester is sometimes also known as masḵara. Gaffary also notes that Jāḥeẓ, in Ketāb al-tāj, a text based primarily on Persian sources, reported that kings needed attendants, including jesters (możḥeks – note the related term możḥekān, meaning ‘comics’), whom he distinguished from satirists (ahl al-hazl).
Karīm Khan Zand (r. 1751-79 CE) is said to have had jesters, with titles such as moqalled-bāšī (chief mimic), masḵara-bāšī (chief buffoon), and lūṭī-bāšī (chief rogue). I quite like the title of Chief Rogue – a new variant on the mock titles that are occasionally attributed to jesters.
Worth also mentioning the word for ‘minstrels’, moṭrebs.
Please let me know of any further jester related lexical material relating to Persia (or other places).
Sources: Jāḥeẓ, Ketāb al-tāj fī aḵlāq al-molūk, A. Zakī (ed.) (Cairo: 1914), p. 21; Gaffary, Farrokh, Encyclopædia Iranica, VI/6, pp. 611-614, s.v. ‘Dalqak’; personal communication with Reza Sabri-Tabrizi; Halabi, A.A., `The Development of Humour and Satire in Persia with Special Reference to ‘Ubaid-i Zakani’ (doctoral thesis, Edinburgh University, 1980), p. 72; Zakani, ‘Obeyd-e (14th century), The Ethics of the Aristocrats and Other Satirical Works, trans. by Hasan Javadi, Middle Eastern Series, 11 (California: Jahan Books, 1985), p. 96 and 124