The Collaborative International Dictionary of English v.0.48:

Insecable \In*sec"a*ble\ ([i^]n*s[e^]k"[.a]*b'l), a. [L.
   insecabilis; pref. in- not + secabilis that may be cut: cf.
   F. insecable.]
   Incapable of being divided by cutting; indivisible.
   [1913 Webster]