We don't have synonyms for purse string yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are purse strings.
(n) :
Alternative form of pursestring. [A cord or string, the middle of which is enclosed in the hem of the opening of a soft purse or sack, that, when pulled, closes the purse.]
(n) :
Alternative form of pursestring. [A cord or string, the middle of which is enclosed in the hem of the opening of a soft purse or sack, that, when pulled, closes the purse.]