Open English Wordnet
Adjectives
(s)endless, eternal, interminabletiresomely long; seemingly without end“endless debates”, “an endless conversation”, “the wait seemed eternal”, “eternal quarreling”, “an interminable sermon”
(s)dateless, endless, sempiternalhaving no known beginning and presumably no end“the dateless rise and fall of the tides”, “time is endless”, “sempiternal truth”