Clue: Turkish headgear? Such a thing a huge number turned up (6)
Answer: CALPAC
Explanation: Definition: Turkish headgear
Reverse of CAP (headgear) + LAC (also lakh, the number 100,000 in India etc). The alternative spelling KALPAK was, slightly controversially, clued in Azed 1868 as an indirect anagram of Jerome K Jerome's middle name, Klapka