Sentence:  Him the Almighty Power / Hurld headlong flaming from th' Ethereal Skie / With hideous ruine and combustion down / To bottomless perdition, there to dwell / In <WSD>Adamantine</WSD> Chains and penal Fire, / Who durst defie th' Omnipotent to Arms. 
Meaning of the word marked with <WSD> tags:  Made of adamant, or having the qualities of adamant; incapable of being broken, dissolved, or penetrated.