Senses
头子/ 頭子 boss
leader of a group; chieftain or gang leader, often used with a negative connotation
头子/ 頭子 [suffix]
(informal) a suffix for certain nouns, similar to 子
头子/ 頭子 official warrant
(archaic) an official document or order issued with a date
头子/ 頭子 best
(colloquial) the best of something; a winner