unbound

Not bound.

(not comparable)Not obligated.

Near-synonyms: unconstrained, unrestrained, unencumbered; unfettered, fetterless

The terms of the contract inadvertently left certain unbound aspects to subjective interpretation.

(not comparable)Not tied up.

Near-synonyms: unfettered, fetterless, unrestrained, unchained, unshackled, shackleless, unmanacled, unhandcuffed

The hostages' hands were left unbound.

ungebunden

not restrained or tied down by bonds

(not comparable)Without a binding.

an unbound book

(not comparable)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.

Helium-2 is unbound, as it is energetically favorable for it to split into two separate protons.