Board Thread:General Discussion/@comment-32074302-20170522075026

"Pay it, aye, thought Theon. Pay it with false coin. Jon Snow would see through the impostesure at once. Lord Stark's sullen bastard had known Jeyne Poole, and he had always been fond of his little half-sister Arya".

Could anyone help me to figure out what "impostesure" means? 