What is the meaning of Unbound?

simple past and past participle of unbind

Not bound.

  1. Not obligated.

    Not obligated.

    Not tied up.

    Without a binding.

    Lying beyond the proton or neutron drip line; having a negative particle separation energy; capable of decaying by the spontaneous exothermic emission of one or more nucleons.

    Source: wiktionary.org