unˈcustomable,a. [un-1 7 b.] †1. Not according to custom; unusual. Obs. 1387Trevisa Higden (Rolls) VIII. 241 Þe pope greved þe chirches of Engelond wiþ taxes..undewe and uncustemable.1570Levins Manip. 4 Vncustomable, inconsuetus. 2. Of goods: Not liable to pay custom. 1727Bailey (vol. II).