We don't have synonyms for dekek yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are deke, derek and deek.
(v) :
(transitive, Northern England, slang) Alternative spelling of dekeck. [(transitive, Northern England, slang) To pull down the trousers of a person quickly and without consent, as a prank.]
(v) :
(transitive, Northern England, slang) Alternative spelling of dekeck. [(transitive, Northern England, slang) To pull down the trousers of a person quickly and without consent, as a prank.]