I. ikˈspendəbəl, (ˈ)ek|s- adjective
: that may be expended: as
a. : normally used up or consumed in service
such expendable supplies as pencils, ink, and paper
b. : more economically replaced than rescued, salvaged, or protected ; specifically : sacrificed according to plan in order to accomplish a military mission
in a war anything can be expendable — money or gasoline or equipment or most usually men — W.L.White
II. noun
( -s )
: one that is expendable — usually used in plural
when an army is retreating, a small force is left behind to cover the retreat and be sacrificed to the enemy: they are expendables — Drew Pearson