'indefinitely-kept' originates from the combination of 'indefinitely,' which comes from Latin 'indefinitus,' meaning 'not defined,' and 'kept,' the past participle of 'keep,' from Old English 'cēpan,' meaning 'to seize or hold.'

'indefinitely-kept' combines the adverb 'indefinitely' with the past participle 'kept,' forming a compound adjective used in modern English.

Initially, 'indefinitely' meant 'without a defined limit,' and 'kept' meant 'held or preserved.' Together, they convey the idea of something being maintained without a time limit.