eternal in WordNet English dictionary

1. continuing forever or indefinitely
   "the ageless themes of love and revenge"; "eternal truths"; "life everlasting"; "hell's perpetual fires"; "the unending bliss of heaven"
   ageless  aeonian  eonian  eternal  everlasting  perpetual  unending  unceasing 
   
2. tiresomely long; seemingly without end
   "endless debates"; "an endless conversation"; "the wait seemed eternal"; "eternal quarreling"; "an interminable sermon"
   endless  eternal  interminable