This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Being or seeming to be without an end; endless. See Synonyms at continual.

adj. Tiresomely long; tedious.

adj. Existing or occurring without interruption or end; ceaseless, unending.

adj. Without termination; admitting no limit; boundless; endless; wearisomely protracted.

Without termination; endless; having no limits or limitation; unending; long drawn out: as, interminable space or duration; interminable sufferings.

Synonyms Limitless, illimitable.

adj. tiresomely long; seemingly without end

"Michael, full grown, mature, was so merry-hearted an individual that he found all delight in interminable romps with Scraps."

long   

infinite    boundless    immeasurable    illimitable    endless    limitless    unlimited    unbounded   

determinable    terminable   

endless    unending    dreary    tedious    lengthy    fruitless    dismal    uninterrupted    monotonous    perilous