indefatigability n 1: tireless determination [syn: {indefatigability}, {indefatigableness}, {tirelessness}]
Indefatigability \In`de*fat`i*ga*bil"i*ty\ ([i^]n`d[-e]*f[a^]t`[i^]*g[.a]*b[i^]l"[i^]*t[y^]), n. The state of being indefatigable. [1913 Webster]