English Pronunciation IPA(key): /ʌnˈbaʊnd/ Audio (Southern England):(file) Rhymes: -aʊnd Verb unbound simple past and past participle of unbind Derived terms unbounded Translations simple past of "to unbind" Dutch: ontbond (nl) sg, ontbonden (nl) pl past participle of "to unbind" Dutch: ontbonden (nl) Japanese: とじていない (tojiteinai) Adjective unbound (not comparable) Not bound; not tied up. The hostages' hands were left unbound. Without a binding. an unbound book 1880, William Blades, The Enemies of Books, page 40:Beneath an old ebony table were two long carved oak chests. I lifted the lid of one, and at the top was a once-white surplice covered with dust, and beneath was a mass of tracts — Commonwealth Quartos, unbound — a prey to worms and decay. (nuclear physics, of an atomic nucleus) 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. Derived terms unbound state Translations not bound or tied up Bulgarian: несвързан (bg) (nesvǎrzan), свободен (bg) (svoboden) German: ungebunden Latin: solūtus (la) Sanskrit: अदिति (sa) (aditi) Swedish: obunden (sv) without a binding Bulgarian: неподвързан (nepodvǎrzan) Ido: broshita, nebindita Wikiwand - on Seamless Wikipedia browsing. On steroids.