frangible
Able to be broken; breakable, fragile.
A certain learned and curious Author gives us the following Characters or Properties of Glaſs, whereby it is diſtinguiſh'd from all other Bodies, viz. […] That it is frangible when thin, without annealing.
Where it comes from
From Late Middle English frangible, frangibil, from Middle French frangible, or from Medieval Latin frangibilis, from Latin frangere (from frangō (“to break, shatter”), from Proto-Indo-European *bʰreg- (“to break”)) + -ibilis (suffix forming adjectives indicating a capacity or worth of being acted upon).
Adapted from the Wiktionary entry frangible (CC BY-SA 4.0).