In·fran'gi·ble adjective [ Prefix in- not + grangible : confer French infrangible .] 1. Not capable of being broken or separated into parts; as, infrangible atoms. « [ He] link'd their fetlocks with a golden band Infrangible .» Pope. ... Found on http://www.encyclo.co.uk/webster/I/56
that cannot be broken or separated; unbreakable: infrangible moral strength. · that cannot be infringed or violated; inviolable: an infrangible rule. Found on https://www.infoplease.com/dictionary/infrangible